Hello everyone,

Finally the steam achievements are implemented! I plan on adding more in later patches!

added:
- 36 steam achievements
- achievements for beating the game with each character on normal and hard difficulty
- achievements for collecting credits
- achievements for completing challenges
- achievements for exploring rooms
- achievements for destroying enemies
- and several special achievements

changes:
- code rewrite collecting credits
- code rewrite for saving stats

fixed bugs:
- armor collecting for player 2
- lil buddy following player 2