[x] Figure out why sometimes player can't move one way but can jump and move the other way.
Happens when moving between two ground platforms but not always. I guess the player's getting caught on a lip between the two grounds, though it's weird that doesn't always happen, and that it happens at all. Both grounds are at the same height always.
[x] Make it so that problem doesn't happen.
[ ] Make it so the player doesn't get bounced up by moving between ground objects.