I'm really sorry to hear that! I'm aware of this issue and I'm still not exactly sure why it happens. I've tested the game myself on 2 different desktops and 2 different laptops. The game works perfectly fine on both desktops (one was a weaker machine) but the game slowed down to 0.5 speed on both the laptops and maintains that speed consistently for some reason. I'm certain it doesn't have anything to do with the enemies since I've made sure there are only about 4-6 instances present at a time throughout the whole game since they only spawn close by (they despawn during boss fights as well)! The palette switching system is quite simple too, there's only 3 layer effects that function as color replacements and only 1 palette can be rendered at a time! My guess for the slow-down issue is that the game is using the laptops' integrated graphics instead of the dedicated gpu but if that's the case then I unfortunately have no control over fixing it anytime soon since Gdevelop doesn't give you a whole lot of options on how your game is rendered... I'll try to forward this issue to the gdevelop forums and see if I can get any help! Thank you for taking the time to write this comment and for playing the game!