Going Under

You will first have to unlock the True Founder dungeons. I wouldn't recommend doing this before beating the game, but you're more than welcome to give it a shot beforehand.



Once you do, the Impostor will show up and trigger a mini-boss fight at the last room. Defeat the Impostor here to unlock Impostor Mode.

Impostor Mode is a 10-floor challenge, 2 floors of each dungeon followed by the vanilla boss, with the Impostor on floor 10. At floor 5, the dungeon becomes the Founder dungeon. Dungeons are not in a specific order. Extra health from the main mode has been disabled, so you will only come in with three hearts. Mentors and pinned skills are disabled. Mentors can be purchased at various levels; for example, you may buy Swomp at level 1, which allows you to shoplift, but doesn't give allies on each floor, as that requires level 3.

As always, assist mode does not disable achievements, so feel free to activate as many as you'd like. Given the nature of the game, a more in-depth guide isn't necessarily possible. Practice in the dungeons that you struggle with, grind for cubits to buy better skills. In terms of mentors, Swomp's ability to get a free item from the shop can't be overlooked. Tappi's extra money can come in handy if you get her early enough. Kara is alright, though much better at high levels. Ray is only worth it at level 2 and above for extra skills, going into debt is pointless. Fern's Fizzle cans are also alright, but you can do better.

Try to have a blank card on hand for the Impostor Fight to get her for the rolodex. However, she is a two-stage boss, so don't use it on her human phase! The wall of the arena is lined with replacement weapons.

The first phase involves timing your hits. The Impostor will dodge most of your hits, so don't expect to button mash your way to victory. The best time to strike is typically the moment after dodging an attack. If you've already beaten the game, this is very similar to how the final boss is damaged. The other notable attack is splitting into several copies. These copies do not have the same weapon, nor do they dodge at the original's rate, so these you can smack around.

The second phase turns her into a half-spider creature. While the ability to crazy dodge is lost, it's still roughly the same strategy; dodge and land a few hits before getting ready for the next dodge. Ideally, you can land the final blow with the blank card and add her to the Rolodex rather than trying to do it in Overtime.