Fun game but I couldn't beat level 5. I'm pretty sure I had the sequence right, but could just as well be that my brain stopped working :)
I also had the issue with the game being too big for my monitor, but turning on full screen in the options solved that. If you're unable to scroll/pan with your mouse, then use the arrow keys to navigate. You have to go up a couple of times, and then right until you see the full screen switch.