I've read that performance can be noticeably improved by disabling Collisions on all sprites that don't use them. My game doesn't have any "on collision with" checks, but it does have a whole lot of overlapping checks. Do those checks require collisions to work, or can I go ahead and disable absolutely all collisions?
My games runs at 60fps on my PC normally, 30fps in debug mode (making that mode confusingly pointless for usual performance measurement?), 25fps on my Galaxy S6, and 2fps on my third gen iPad. I'm aiming for 60fps on modern phones, and 20-30fps on my old iPad.
I'm resizing images where I can. If I have a sprite and image sized at 1024x256, resize the image to 512x128, but keep the sprite sized at 1024x256 (so slightly blurred image quality) would that improve performance because the image is now much smaller, or make no difference to performance since the sprite is the same size as it was before?