v0.7 - Gravity and stuff

I finally got the time to update the game a bit. 

I've setup 5 levels that should work as tutorials in the future, simple stuff really.

Probably the big piece of the update is the added gravity forces that pull the player's ship towards asteroids. Gravity also scales depending on the size of the floaty space rock.

Note that this is not me just piloting around the asteroid :)

Also, now the ship has no inertia dampener, it will constantly float toward the direction you apply force to. It should add some learning curve, i hope it's not to hard.

One last thing i added in this update, is the ability to teleport from one side of the screen to another, without loosing violence, speed or momentum.

I really hope you enjoy, and if you got any question feel free to use the discussion board down here :)