Although simple in its design and concept,this game is engaging enough to kill some time and with or without medals,it is also quite addictive for players wanting a challenge(this game is more of a 'normal' difficulty which makes it playable for everyone.)It might be better with more types of obstacles that can 'bounce' off the walls and not just move in a regular way,as it can get too 'predictable' even in the later levels.The levels could be designed using other shapes besides circle and it could make the game more interesting(for example,a squareish level is smaller but has less obstacles than a rectangular level,obviously.)Anyway,good work on this simple yet quite enjoyable game.