Regular update - 0.6.4

Version 0.6.4 is out, new features and a few corrections for today !

1. Add a select character functionality : when starting a new game, you can now choose a cat model, between 7 cats available.
2. Add a quick access to unlocked mini-game : when you discover a mini-game and finish it at least one time (with any score), you unlock direct access to it, available in the player menu. With that, you can access to this mini-game from anywhere.
3. Modify some physics and friction of the cat, smoothing movements and fixing some glitches.
4. Fixing some building on the terrain, especially in the end game zone.
5. Fix an issue coming when loading some save game, blocking the loading.