Update Version 0.2.1a

I's patch day! I've been working on some Bugfixing and creating others... :) 

* In the boss final phase, now the player can't dodge while i'ts attracted by the "Gravity Bullet"
* Fix some issues in the UI menu and the How to play menu section,
* Some enmies moves even if the game is paused, now they can't.
* I've started refactoring some code things, for now nothing should change.

That's all, I think this will be the last update for, at least the following 30-40 days. I've been working on the next Update: 0.3.0a