I'm not sure I understand what you mean with a timer? The only timer I have in the game is one that checks if Bob hasn't moved for a couple of seconds, to prevent becoming stuck . The game over on wall collision needs to be there to prevent you from simply moving through walls.
Regarding the cheese, did you manage to move around the button in the last level? I didn't think it was possible, but if so, then well done. Giving more than exactly needed is also a bit of a red herring, though in some cases it can make the puzzle easier than intended I guess.
Your last point is 100% valid: I basically wanted to make many more levels, but ran out of time fixing other issues. So it's more of a tech demo than a game I think, all it does is present new mechanics in fairly simple puzzles.
i think it was this level but bob kept touching the centre wall barely and i had to redo it a couple of times, by the timer i ment that a simple colision where bob stops on colliding with a wall would have been better and did not know that a timer was already being used :p 
Gotcha, the problem is, once Bob hits the wall, he either dies or stops and in both cases you would have to redo the level.
I've had the same issue in this specific level too, wish I'd hide the controls panel once you pick up a block to place, because there is more space than is actually visible now.
