Going Under

This achievement is for beating Imposter Mode on Overtime 7 which is the ramping difficulty element of this mode. You start on Overtime 0 and each successful run allows you to raise the difficulty via a modifier that changes elements of the base game's normal gameplay. These modifiers stack on top of each other so you can imagine by the later Overtimes there may come some difficulty in succeeding in runs. If you would like to see a list of each Overtime's modifier, these are listed at the bottom of this post.

The runs consist of all 3 dungeons back-to-back and then a final Imposter boss.

If you would like to know how to start Imposter Mode please see:




This is rather a collection of tips and a thorough guide to how I personally got this achievement for beating Overtime 7. Hopefully anything from this post helps you over that hurdle you may be struggling with. This is just my personal experience so feel free to post your own comment if you have any more advice to help players with Imposter Mode.

Assessibility Mode:
If you haven't already used this, put this on. There's no shame in this, Imposter Mode is sometimes even a struggle with this on fully.

Perks:
'Thick skinned' is the best perk in my opinion, blocking all projectile damage. When you've got this perk you'd be surprised how many times this actually saves you damage throughout the run.
I also personally loved the perk 'Free Hand', that made 2-handed weapons be wielded in one-hand. This makes your attacks with these weapons so much faster, and worked with my play style, which will be addressed further down.
Both of these perks were insta choices for me, I would always buy or pick them, even in the runs later on in Overtime 5 and above where you take damage from picking up skills. The damage you save by having these outweighs the half a heart damage to pick em up.
I feel this also applies to any skill that gives you an ally such as the flying drone or floor drone with a knife attached to it. These take the aggro away from you on countless occasions and therefore save more damage taken then it costs to pick them up.
Nearly all other skills in my opinion aren't worth the pick up on Overtime 5 and above, so I would simply not pick them up to avoid the damage, sticking only to those mentioned.
There may be some others you personally like where it is worth taking it on the later runs for you, see how you feel in the situation.

Obviously until you get to Overtime 5, still continue to choose the perks from the perk rooms that you like, as there's no downside to them yet, but prioritise those mentioned above if you see them as a choice.

Money:
Save your money to purchase food items to heal, this is where nearly all your money will be spent in runs. If your health is doing okay and you've got good money, the health increases are always a good bet. I would only buy the skills in the store if they were ones mentioned above. If thick skinned is in the store, buy it always. Only time I would ever buy the weapon would be if it was the tablet pen during the Joblin runs, as having this weapon, or even two, for the boss is a free win and always worth the 6 money or whatever to take 0 damage from the boss.

Mentors:
Only time I personally bought the mentors was the first dungeon they are presented were it costs around 12 money. I enjoyed the mentor 'Tappi' that increases your money found throughout the run. If I got this mentor early, the 12 money spent would be returned by so much more during the run and would make it a breeze, being able to buy so many heals throughout. The mentor 'Swomp' that allows you to steal 1 item from every store you visit is also fantastic as you'd get so much for your little money investment. I know some people like Kara for her apps, but I personally preferred these other two.
Later in the run where the mentors cost alot more, around 40, I don't feel it's worth the money to change, especially if you get a good mentor early for 12, they're good the whole run.
But ultimately the mentors are up to you, if you have a personal preference that works for you, stick with that if you want.

Attack style:
My play style preferred quicker 1-handed weapons with medium damage over heavy 2-handed weapons with high damage. The ability to get a few hits in with the quick weapons and then be able to dodge roll out when necessary was way better for me than the slower animation high damage 2-handed weapons. Obviously a 2-handed weapon has its place in certain situations, but I felt overall, i got hit way more mid-animation trying to swing heavy weapons and so stuck mainly to 1-handed when I had the choice.
This is also where the perk mentioned above is fantastic, if you can get the 'Free hand' perk where 2-handed weapons and wielded in only 1-handed, you get the high damage of the 2-handed weapons but with the speed of 1-handed. Was another must for me personally when I found the skill.
I will mention a few key weapons in the individual dungeon section below.

Also I'll mention that I never used the focus feature at all while playing, not sure if you do or not, but that's just how I played the game. I simply preferred the normal camera and then would dodge roll away when attacked, felt I had more control over the dodge roll this way.

Apps:
You should always use the apps you're given of course, no reason not to get the benefit they give, but two are great to hold onto until the boss of the dungeon you're on. The app that turns you into a car is great free boss damage when you need it. If I got this in my final of the 3 dungeons I would honestly hold it til the imposter as it's almost a free win on that bosses 2nd phase it does that much damage to it.
The app that turns all items around you against enemies is also fantastic for bosses, in winkydinks and Styx in particular. All the items will fly towards the boss and keep doing so until they are broken, it's great damage. Can't remember the name on hand but it's a blue app.

Curses:
During my normal base game playthrough I regularly took curses from the curse room, however during Imposter Mode I did not take curses at all. There's no need to make it harder for yourself. Especially when the reward usually isn't worth the chance of you taking more damage from having the curse active, keeping healthy is everything in this game mode.

Job rooms:
These are the rooms were you have a choice whether to do the combat or not.
In terms of the job rooms in each dungeon;
Joblin job rooms are easy and I would always do them on all runs.
Winkydinks rooms where you can choose a match, fight an elite type enemy and then gain them as an ally. I personally ignored these rooms all together and would just run through them. I felt it wasn't really worth the damage taken in these type of fights when you can easily just not do them and most of the time have more health because of it.
Styx rooms where you have to kill all the enemies in a certain amount of time to get all the money and where money is scattered all around the room. This room I found the hardest of the bunch and as I increased the Overtime as I went along, I found the best thing to do honestly is either ignore them entirely in order to not take anyway damage. This is because even if you succeed, 80% of the time you would have taken damage in order to clear the room quick enough, but as stated earlier, your money is spent on just healing yourself anyway so doing the room basically cancels itself out. So what I would do is activate the room, but have no intention of killing the enemies to clear the room, simply try and collect as much money as you can off the floor safely in the time your given. It's a free little bit of extra money if you play it safe taking no damage.

The rooms with an item on the pedestal in the middle of the room, I also did not do these, unless on the rare occasion the 1 heart health upgrade item was there.

Joblin Dungeon:
Weapons I used were mostly the 5-6 damage 1-handed sword or mace, these were my bread and butter. They allowed for aggressive attacks killing enemies before they can react and get an attack off, and also allow dodge rolls to be used effectively against the bigger enemies.
The 2-handed 8 damage club is also pretty good, especially if you get the perk I've mentioned.
I'm sure you'll have other key weapons that you've preferred throughout playing so far, whatever kills the enemies while taking the least damage yourself, use those.

If you find a tablet shock pen, keep it in your inventory and don't use it, try to hold at least 1 of these until the boss as you can stun lock him and get a free win basically. The boss room usually has one on the wall so keep an eye out during the initial boss cut scene so you can run and grab it after your first one breaks if you were only able to carry one til the boss room.
Also if you see a tablet pen in the store, buy and hold for boss, it's worth the little money to guarantee a 0 damage taken boss.

Honestly you don't need to know the boss attack patterns for this floor as nearly every run will be a stun lock 0 damage taken kill. Just wait for him to jump attack and when you've avoided it just walk up to him and wail with the tablet pens.


Winkydinks Dungeon:
The best weapon this dungeon has is 100% the low hanging fruit, 1-handed and 9 damage, I would stack my inventory with these whenever I had the chance and used them exclusively most the time. May need to use another arching attack weapon to knock them down from the ceiling.
The swipe attack is perfect for the boss as you can hit both hands with damage in one swing, destroying both hands very quickly to damage the boss. When you spawn in boss room, the hand on your left does a 3 projectile attack so just run left to avoid all 3 while moving closer. When you're near the back wall on the left of the left hand, you can attack right aggressively and hit both hands for a large amount of damage.
2nd phase spawns fire out of the floor tiles initially. Honestly if you've got the low hanging fruit weapons and gotten this far into this game, the boss is easy from here, just make sure to wail on the boss head when he goes down and you should kill it on the 3rd knock down at least.
The hockey stick weapon is also okay at 7 damage but I'm unsure if it is 2-handed or not. Double hockey sticks are fantastic at 11 damage too. The guitar AOE weapon is also great for the boss here as you can hit both of his hands, as well as the floating main head, with each attack

Styx Dungeon:
This was the hardest dungeon for me, and I felt the weapons are the weakest for their area out of the three dungeons. Only go-to weapons out of lack of great options are the standard pickaxe 6 damage, diamond pickaxe 9 damage, 2-handed sledgehammer 8 damage and shovel 6 damage. Shovel is the quickest for single target I feel, and pickaxe and sledgehammer with their swing attacks do well at crowd control. With this dungeon you just need to take your time with it being the hardest, you can lose a lot of unnecessary health.
The boss of this dungeon is Hustlebones, and a huge piece of advice for this is to make use of the minecarts from the start if you weren't already. From the start move to the right minecart, get in and try to hit the boss over and over again on the track, doing as much damage as you can in this first phase before the minecart is destroyed. The minecarts do so much damage it's obscene, helping out alot. If it gets destroyed just keep doing 1 or 2 hits to him and then rolling away to dodge 1 of 3 attacks, his spin attack, down attack and the double attack.
When the boss takes enough damage he'll return to the back of the room (his chair?), where you can't damage him and spawn minions. At this point go jump in the 2nd minecart, flatten the minions with ease and then use the minecart again on the boss when he jumps out from his chair when the minions are killed. Do as much as you can before this cart is destroyed, if you've used them correctly he shouldn't have that much health left for you to chip down with your 1-2 dodge attack style. You may kill him here or he may jump back and spawn another wave of minions. Kill these safely and then you should for sure kill him this time when he returns to fight.

This boss for me is the hardest of the three, and I struggled originally before utilising the minecarts (which are a joke how much damage they do), was almost like I was fighting him on hard mode originally without them. If this is the hardest for you, a good idea may be to abandon runs right away until you get this Styx dungeon first, that's what I did for the final two Overtime 6 and 7 wins. That way you are getting it out of the way first.

The Imposter:
I didn't think this boss is too bad, felt Hustlebones was harder for me. From the start I would just walk forward to dodge the raining damage from the ceiling and go full aggro on her just swinging non-stop, dodging occassionsly. As I would do Styx first I would usually end on winkydinks, therefore having the low hanging fruit or hockey/double hockey sticks in my inventory. These weapons were fantastic to wail on the imposter, but I'm sure any similar weapon would do and the whole arena has a plethora of choices on the walls if you need a new weapon. If you can get her near a wall you can damage her so much without much reply as your hits knock her back but still within range for the next attack. When you've done enough damage she will spawn 2 clones in next to her, but with that style of weapon I was using I would just still keep wailing on the real imposter with swipe attacks and would hit the clones indirectly. Once you kill the main one the clones despawn anyway so focus the real her.

After you take her first health bar down she transforms into a spider-bot thing, here's where's a great place to pop the car app, but it should still be a win if you get to this stage even without it. Attack her as usual and throw in a dodge roll after 2-3 hits to dodge her attack. After a bit she will sort of crouch down and start doing a spin attack, just completely avoid her for the next 30-40 seconds or so. She spawns a boot in that will track you from the sky and then do a down attack once, but simply dodge this. Beware her bouncing off the walls while spinning as this can hit you if you've not been looking where she's at, just dodge roll left or right when she comes at you.
After this time she will go back to simply walking in the spider form and you can go back to hitting her a few times and dodging. You should be able to kill now in this stage, unsure if she goes into the spinning attack again but if she does then just do the same to avoid her as above. But using all this you should be able to kill her fine if your health is decent, just don't get unnecessarily greedy.


Hope at least some of this can help any players starting Imposter Mode soon. As I said at the start, feel free to comment any other key tips that helped on your own runs, thanks.

Thanks to rhodzyy and DubstepEdgelord for their advice towards this, especially in suggesting the minecart's importance for that section.


Here's a list of the Overtime levels for anyone interested:

These difficulties stack on top of each other.

Overtime 0 - No additional challenges
Overtime 1 - Enemies from other dungeons will occasionally invade
Overtime 2 - Powerful enemies appear more often
Overtime 3 - Start each dungeon cursed
Overtime 4 - Bosses spawn additional minions
Overtime 5 - Take damage when learning skills
Overtime 6 - Take double damage during the final combat on a floor
Overtime 7 - No mentors. No Health upgrades. No hope. The world is not fair.