Thanks a lot for playing and obviously reacting to it. I've fixed the browser fullscreen. The levels were actually well-connected. Level 1 -> 2 >3 >1. Yeah, you're right that the input area should have been cleared. But honestly, I tried to do that, and nothing worked. Got a bit frustrated at that part and just left it as it is. I started late and the time was surely something I had to consider. I'll surely clear that on the new build. Thanks for the idea of coloring the keys and safe.
Thanks again and cheers Man!