still working my way through demos since I've been busy but going to quickly go over the ones I did and didn't like so far:
liked:
Öoo: extremely short but fun, not sure how the mechanics will work out over a full game but what I saw so far in the demo had a decent amount of promise, some of the timing-oriented stuff towards the end felt a little awkward but I can see how it'd be fun to overcome like rusted moss's grapple system or something
MotionRec: another short but fun one (although double the length of Öoo's demo), had a couple decent "aha" moments; I have the same issue of not really being sure how the mechanics will work out over a full game since it feels like things were already being pushed a bit in the demo but I can see it being really fun with the right execution
UVSU: I liked the blend of action and puzzle oriented stuff with the 'fighting yourself' mechanics (although it started learning much more puzzle later in the demo), has good potential and the demo is pretty fun (and feels more expansive than the other two platformers above)
Occlude: I'm a sucker for well-executed solitaire variations and it definitely delivers, the added mechanic of having to figure out the extra conditions for each deck makes it a lot of fun to sort the rules out your first time around and the rules continue being fun to play around in subsequent hands, I can see myself coming back to the demo just to play it and I'll probably get the full thing on launch depending on price
Texnoplazm: Good action combat, makes you feel strong and powerful while still providing some level of challenge, I like it hinging a lot more on melee than ranged combat like most games in this vein, navigation felt awkward at points but I'd always figure out where to go fast so I can't complain
Sinker Sound:
absolutely ruined me my first 10 or so attempts since it's overwhelming, quickly became very satisfying and fun once I adapted, the music and cute psp-ish graphical style also does a lot for me