The game is perfectly Valve-like and this is quite a compliment. Still, the only thing bad about the game itselfis the choice of control setting. To make it perfect, it needed the same Portal pc version system (each mouse button assigned to a portal), but it is something that might have been impossible to implement here. Still, the game runs well (even though there are some levels hard to understand as it would imply using the slightest inch of distance to make it work, which is difficult to use when jumping distance is not so high.
Still, quite a good game.