I gave the demo a whirl and was impressed.  It already surpasses many shareware era platformers.
I noticed some issues with the ladders.  You can exit them too early.  That's OK.  I had similar problems with Inferno.   Easy to fix!
I really like the music.  It's proper use of SID sounds.
My only complaint is that you can't duck.  I want to duck under the bats, but can't.
Presentation and aesthetics are straight up 1993-4 era DOS games, though.   It's pretty good.