Collectibles & better code

Division into more classes and working counter for collectibles.

Now with lives and moving platform!

Merge pull request #9 from TotallyNotAB0t/BranchForModifications

Added moving platform

Real death and checkpoints

There's also a little frog that you shouldn't touch.

First release with base features

Current features in this version :

• Movement of the player on the X & Y axis
• Jump movement
• Sprite facing the direction you are moving
• Saw that kills the player
• Restart mechanic when touching the saw
• Every movement animated, except death.
• Small Menu with 2 buttons : one to switch to the game scene, the other to quit the app