I appreciate the feedback! I'm very glad to hear you think the graphics fit the era I was going for, and that the controls are smooth (I probably spent the most time making sure Kreena's controls and physics were clean and fun).
I did, actually, compose a short music track to play throughout the duration of the demo, but so many things broke on me that I had to make small sacrifices in order to ensure I'd have something functional to submit, heheh. Them same goes for the enemies: I actually had 5 designs that I'd scribbled out in an hour or two-- all except for one I managed to get quick sprites animated for. If I'd had just one more day (or if the map hadn't completely broken down and lost me a day) then I might've implemented them all, and given them proper logic.
Thank you for the encouragement, though! I am continuing development as we speak, so expect to meet the rest SEN-86's native monsters (and the threat they pose) real soon!