Math Missile Defender - new levels

New planets, new math tasks to destroy the missiles. 
2 way multiplying, adding. 
3 levels so far. 
Some polishing on visual things (laser beam, text, etc) 

Quick bug fix: slow down in browser version, HUD mismatch

Code: Used some simple instances and particle effects. Shake effect with built-in effect function of gamemaker, it seems to be really easy to apply. Different levels has different layer coloring effects.