So far I have found:
Entering the tutorial and then going back to the main screen will always bring up the option to resume current game. This brings up three different results depending on what ending you got last: getting a death ending will play the game in real time speed with living enemies aiming at the position where you died. Getting an ending where you go through the gate will simply let you pick up where you left off, and getting an ending where you destroy the shop plays the game in real time and makes you invulnerable, as well as making it impossible to get to the next round.
Unlocking the gate and entering the tutorial opens up an invisible space where the gate would be.
The times where being close to an enemy seems to make bullets work less often? I haven’t exactly figured out what causes them to not deal damage but I can do it pretty consistently
Also, did you purposely program drones and lurkers to be able to crash into walls, making them commit suicide?