Thank you so much! Glad you liked it :). Hah yeah I'm not too into puzzles either. The windows I owe to the benefits of having the whole world loaded (so there's actually something to see outside them) plus a cool refraction effect I used which I did not write :).

Yeah Unity. Unity is completely free! You can ship a commercial game with it and make money. The free version has all the features of the full version. I find their pricing model absurdly and impossibly cheap ¯\_(ツ)_/¯.