Nickelodeon All-Star Brawl 2

The Campaign mode of the game is actually a roguelite mode. You need to fight through battle after battle, with shops and minigames interspersed between them, where you can choose between a randomized assortment of powerups to buy, which help only on the existing run. During the runs, you'll get three types of currencies:
 

• Green Slimes - used to buy and upgrades perks in the hub
• Blimps - used during runs only, to buy stuff from the various shops. Blimps reset after each run
• Purple Splats - used to upgrade the shop (so it has more perks available to buy) and to unlock more perk slots in the hub

Initially, you'll want to go for Green Slimes and Purple Splats as a priority, so you can get more perks and upgrade them when back at the hub. Here is how the campaign is laid out, in distinct runs. This is, of course, assuming you are victories on each run. If you die and lose all stocks, you're kicked back to the hub and will need to start the current run over again. Here's how the campaign mode works:
 

1. Run 1 - you'll go through a relatively simple set of arena (wave) stages, powerup stops, and fights against mind-controlled characters. This run is essentially set, not randomized, and acts like a tutorial of the mode. It ends with a fight against King Jellyfish. Beating this boss unlocks Jellyfishing (30G), counts as a completed run (unlocking ACTIVATE THE PLOT DEVICE! (20G)), and then sends you back to the hub. NOTE that this is the perfect run to do Unleash the DOOM! (100G) on, because it's the easiest and shorts run in this mode. Refer to that achievement solution for more information.
   1. As a side note here, I highly recommend that you head to the perk shop and buy and equip the perk that starts you with more stocks on each run. Upgrade it if you can.
2. Runs 2, 3 and 4 - these three runs are all the same, for ridiculous story reasons, and they're three times the length of the first run and more difficult (which is why they're terrible choices for Unleash the DOOM! (100G)). Instead of a single length of battles, minigames, and stages, culminating in a boss fight, there are now three of those back to back. It all counts as one run though, so all of your powerups and purchases carry through for the entire thing. This also means you need your stocks to last you through all three stretches and bosses, which is why I highly recommended purchasing the perk for extra stocks, and upgrade it between runs. Through the three stretches, you'll fight a random boss at the end of the first and second stretch (it'll either be King Jellyfish, Shredder, Flying Dutchman, or Sartana), and the third stretch will always end with a fight against Lord Plasmius. Beating Lord Plasmius ends the run and sends you back to the hub to prep for the next run.
   1. Note: Use your Purple Splats to upgrade the perk shop as a priority. Upgrading it to level 3 is how you The Journey is the Destination, Man (30G), NOT by purchasing every single perk with Green Slimes. If/when you have enough Purple Splats and want to add a second perk, the one that heals you when you apply a debuff is really good. During runs, at a powerups person or shop, look for the powerup that lets charge attacks apply a debuff to enemies. This is not only really strong and helpful, but with the perk mentioned above, it's the best way to heal during a run. Arena battles against waves of enemies now become places to heal, because you'll be doing charge attacks against them constantly, constantly applying debuffs and constantly healing. Use your Green Slimes to upgrade the perks for more stocks and more healing on debuffs, and you'll easily max out the latter after your second or third run, unlocking Research Complete! (10G)
3. Run 5 - this is the final one. It's identical to the previous three runs in terms of length of how it progresses. Clockwork will show up during the first shop of each stretch, but that's the only difference other than the boss at the end of the third stretch will be Clockwork instead of Lord Plasmius. Focus entirely on Blimps and shops to spend the Blimps to get as many powerups as possible, since this is it. In the end, Clockwork ended up being a piece of cake that literally didn't even hit me. Just spam charge attacks on him and stay behind him, and he'll barely hit you, if at all
   1. After beating Clockwork and ending your fifth run, you'll be back in the hub. Talk to Clockwork and then head to the portal to beat the campaign's story and unlock this achievement. Note that you will be back in the hub after the credits and free to do more runs or buy whatever

On the easiest difficulty (which you can switch to any time during the campaign, from back at the hub), most fights won't cause any problems.
 

• In the Arena fights, do your best to keep all enemies on the same side of you so you don't get surrounded, and just keep doing charge attacks over and over. It only takes two or three to send most enemies flying off the screen. Some bigger enemies later will take more, but thankfully none of these enemies do much damage to you. Also during Arena fights, stay alert for food drops. Pick these up to heal.
• In fights against mind controlled opponents, be careful because they can do a lot of damage and send you flying pretty easily, even on the easiest difficulty. I used my same tactic from Arcade: stay stationary near the middle of a platform so you're relatively safe, and charge a smash attack while waiting for them to approach you. Keep doing this until you beat them
• As a side note here, as you unlock new characters, I recommend switching. Spongebob and Patrick are pretty bad. I switched to Raphael when I unlocked him becauase his charge attack does two hits, which means twice the chance of inflicting a debuff and therefore twice the chance of healing
• For splitting paths, plan out what you want/need. In early runs (the first two or three), maybe you want to go for Green Slimes or Purple Splats here and there to upgrade or add perks for the next run, but for your final run(s) (definitely the final run, and maybe the penultimate), Green Slimes and Purple Splats are useless. All that matters is getting through the run, so focus on Blimps and head to all the item shops you can, to stack up powerups for the boss fights. Save up Blimps if nothing is good (absolutely don't waste Blimps on buying Slimes or Splats at shops), because you might find a shop that sells stocks for more lives.
• For boss fights, just spam charge attacks on them. You unfortunately can't inflict debuffs, but it does good damage, and if you got lucky enough to find a powerup where charge attacks also have a chance to grant you a buff, this is incredibly good. You can even have multiple buffs on you at once, making boss fights that much easier. There's still a chance you'll die on a boss fight, but it should never be more than once, and with the perk for more stocks, you can afford to die once per stretch and still make it through the run

Considering you'll be doing four runs with multiple bosses on each, you'll assuredly see all of the bosses necessary for the achievements below. I finished them all by the middle of my third run of five. When you finish your fifth run, beat Clockwork, return to the hub and talk to Clockwork, then enter the portal, you'll finish the story and unlock this achievement.