Day 10
Fixed a bug where colliding with enemies wasn't causing Ace to take damage. However, after the fix I ended up making Ace take TOO much damage. If I'm gonna check for collision every frame, I need to give Ace some clemency as an 8x8 object colliding with other 8x8 objects. First, I refactored the code so all the effects of ace's collisions are tracked in a single function, and then I made that code conditional on an invincibility counter not being in progress. When the invincibility counter is incrementing every frame, ace is invincible. When those increments hit a certain point (arbitrarily 5 frames at the moment), they cease counting and reset until the next time Ace takes damage.
Added some more enemy placement.