this level has some neat ideas but it needs some work
idk the spikes with layer 3 fog are a pet peeve of mine, it probably doesn't bother other people but is it possible to remove it without being a detriment to the aesthetics?
this series of eeries are a pain to deal with because sometimes, you'll fall right between the gaps and get hit. maybe a wall of 3 individual eeries instead would work?
the fire blasters above morton very frequently got me, too. considering the rushing element of this section, you might want to find a way to find a way to let the player get past it without getting hurt before the fires die down
considering the boss battle right before this, you might want to reconsider having the player die immediately after winning
there are no morton coins in the level. is having them in all the levels something we're aiming for?
the bullet bill generator in the "warm" version of the tank might need to go, there's a particular section with two koopas on a ledge above you that can be screwed over by rng, it's also kinda annoying to deal with anyway
the music in the "warm" version also needs an adjustment, mind if i mess around with the channel ordering so the alarms are actually audible?
the "warm" part also really needs a powerup, perhaps immediately after you exit the pipe. considering how all the enemies in the "warm" section are shown in the "cold" section, perhaps you could have a frozen mushroom in that general area?