Woah there, didn't realise there was still development on this. I have an old version, version 1.24 it calls itself - when the game was a free download and it still works just fine on my current Windows 10 computer. Trouble is I've forgotten how I managed to beat some of the levels (and I never *did* manage to beat level 100) and am currently stuck on level 82. I remember there used to be a video of a full playthrough but it seems to have disappeared...
Anyway, is the "classic" version of the game available in this game as a set of levels? If not, is there a reason that it couldn't be, or could the old levels still be made with the new engine?
One thing I've noticed is the different behaviour of keys and locks, like one key = one lock and you take the key to the individual lock. Rather than taking a key to one lock in one place, and it opens all the white doors in the level at once (and there are sometimes other things that can close them all again).