I tried out a good majority of them. Here's my take:
Bloody Rescue - Very promising, but moves a little too fast, which makes things confusing and ends the game quickly. I also think, personally, that the camera should be panned up some, so you can see more of the playfield.
N-Tris - Freaking fantastic. I loved everything about it. Ah! My Goddess is no longer the best Tetris clone for GP32. The graphics, sound, difficulty, and controls were all excellent. The only thing I would add would be some more music, but that's a small quibble.
LOL Fighters - Looks like it could actually be a fun game. Needs some definite AI tweaking, though, if single player is going to be worth playing at all.
GP FinalWar - Awesome. Nice demo to show off the engine. This game is going to nice once it's done.
Hexafire - Honestly, I thought this beat the hell out of Magic Quest. It doesn't have the graphics of MQ, but it sure as hell is more fun to play. There are power-ups, enemies that actually aim at you, and patterns and waves. The only thing I think it needs is a graphical overhaul. It's a bit muddy and ugly (in my opinion).
Puzzle Mix - I liked this one a lot, too. Five well-playing puzzle games (one that is exactly like Bejeweled). Nice sound, menus, graphics, etc..but it -really- needs some music. After that, I'd say it's gold.
Bichos - I like the idea behind this game, and it controls well. I think it could use a little more animation, and the sound effects are a bit hard on the ears. Some aesthetic tweaks and this would be an enjoyable game.
JBB's ..uh..something OID - I love it. The last version of this game was good, but had off ball/paddle physics, but this one is right on. It has a ton of nice touches such as bricks falling off the screen once they've been hit, and it's really insane to see multiple balls and bricks falling all over the place. One thing I would change, though, would be the speed of the paddle. Instead of it being fast all the time, you should be able to hold down a button when you want it to speed up.
Animings - I think this is by the same guy that did Puzzle Mix. It's a lot of fun, don't let the screenshot fool you. It's a great take on Lemmings, where you have to guide red and blue ants to their holes by guiding them with their own colored apples. Good stuff.
Entropy - Eh. This is a decent start for an adventure game engine, but other than that, it was pretty blah, in my opinion.
Magical Quest - It's got nice graphics and sound, but it lacks so much gameplay. I got sick of shooting the same enemy after 5 minutes. The enemies don't come out in any sort of patterns, and they shoot randomly about the screen. The main sprite is nice, but is far too big and succeptable to taking shots.
GP32 Car - Something like this should be turned into a sort of Super Sprint game. It's asking for it, but simply moving a car up and down to dodge obstacles is too boring.
That's all I got to try. My favorite is definitely N-Tris, but I kept N-Tris, JBB's ..Noid, Puzzle Mix, and Animings, as they're all great. Make sure to give these four a shot.