Linux Build and Game Update (v0.4.0)

Linux build of the game is now available, I have no way to test it so please let me  know if it works alright! 

Also the game was updated, with the following changes.

< V0.4.0 CHANGE LOG >

• 4 new levels (levels 25-28)
• Fixed d-pad and start button on the controller not working
• The warp effect doesn't clip below the game world anymore
• Fixed a bug where sometimes then main menu stayed open with the level select