I gave it another try after getting back to my PC. Without the lagging it's much better :D The puzzles are fantastic and you have some really cool mechanics, like the metal detector. The battle room could be a little more balanced, because if you kill the enemies when spawning then it's too easy, but when you leave too much alive, then you have no chance surviving. Maybe it would be a good idea, to make multiple spawning points, so the player would not have the chance to attack immediately. Also, the player height was a little low for some of the elements in the game and I would loved to hear some ambiance music. Really good game overall, fantastic puzzles, very interesting levels and challenges, not repetitive at all, which I think is really hard to achieve, so congratulations, nice work! :)