Reworked Movement

A few changes have arrived for this update.

Most notably is the updated collision checking so the player doesn't accidentally slide of a building anymore. Before this change, the game would only check one pixel below the player if there was a building, which sometimes led to the player being slightly of from that one pixel resulting in a unjust feeling death. Now there are two invisible boxes following the player cheking if he is near a building instead of directly touching it, disallowing the player to dash before being airborn for a moment.

Other changes include:
- Minor changes to the player hitbox in general
- Slight changes to the background song in-game
- Addition of bats as enemies which have to be clicked to kill.