You can't move and shoot while moving diagonally in all 4 directions. You can move Northeast,Southeast, northwest, but when you try to move southwest then the game locks up and you stand still and just die.
The one thing that i dislike about the perfect system is the boss levels, I'm sorry but fighting a boss after about a solid 5 minutes of stressful avoiding basic enemies and then being asked to handle a boss that can cover a good portion of the screen with attacks is just obnoxious and uneeded stress. Getting to the end of a level without getting hit is hard enough but that last boss is way too much of a pain to avoid getting hit on, even at max upgrades.
I want to like this game on all difficulties, but the curves ruin the game on those higher difficulties. At most you need at least a full second to work through the obstacles but the curves don't allow that.
If there's one thing that I think is holding this back from being perfect it would be the curves. I hate the idea that getting to the obstacles is the hardest challenge instead of the obstacles themselves.
The "fabled apartment" level on extreme has one obnoxious thing about it: the text gets in the way and the bugs are hard to see. If you could move the text to the top of the screen then it would be a much nicer level with less artificial difficulty.
Is there any chance of nerfing Acid as a damage source? It's very frustrating when you are having a good run to be stopped simply because an enemy hit you with it and now you're taking nearly 40 damage and there's another enemy who's waiting to renew the acid.
I think revived heroes need to be able to move because I had a moment where I was in a complete stalemate with the final boss because my last character was blocked by a chest and a dead ally and they couldn't stay alive long enough to move or attack.