I try to make a level, made out of completely spikes and 4 walls. It crashes when I test-press enter. Why does happens?
Is not correct English order, but is understandable.
Too many entities (and with "too many", I really mean "too many"

) on a screen will result in a crash. I don't really feel like looking up the exact amount, but yeah.
Spikes is converted to an entity internally. Other things that do this are 1-pixel-wide quicksand blocks, and the one-way wall thingy.