What I (remember) playing
Luigi's Mansion 2: This is the sequel of the underrated Gamecube title of the same name. I'd say that it's an excellent hark to the original and if you liked the original, you'll definitely like this one. My only complaint would have to be that they use the gyroscope in the 3DS system to determine if where you're aiming your vacuum (up or down). You can imagine how strange it may work on a bumpy ride. What's worse though is that you can't play in 3D anymore because as soon as you tilt the screen, the 3D goes all wonky. Boo on that! Still a must buy for me.
Starfox 64: I got to play the multiplayer version of this game. It's essentially the N64 version, but you play 4-player deathmatch across four separate 3DS systems over bluetooth. It looks better and it controls just as good as the original. You can even invert your Y-Axis via a touch button on the bottom screen (no going to Options for this guy). I also liked how they kept the camera on so you can see all of the player's faces as they play displayed above their ships.
Mario Kart 3DS: Plays like a better looking version of the DS one. Some interesting additions is that after you pick your character, you select your kart, your wheels and your flying contraption (jumps result you floating and whatnot). If you liked the DS one, you'll like this one.
Rayman Origins: This is an excellently HD drawn experience that is like the Wii version of Mario. So it's got four players trying to reach the end of the level by collecting all the gems. The thing that makes it stand out really is the humor (friendly fire is on, but hilarious) and the beautifully rendered graphics. It's so pretty!
Doctor Lautrec and the Forgotten Knights: I love anything like Professor Layton. This one's kind of like that, but you have to actually maneuver the character through each part of the dungeon and there are certain action based challenges like "avoid the guards". The puzzle I played was a crossword puzzle. You actually access the pieces to the puzzle via a drawer on the screen and place them in the right places. I'm not a fan of the 3rd person movement, but I'm just biased. The animation is fun though.
Medieval Moves: I'm actually looking forward to this Playstation Move title. It's basically an on-rails shooter, but is more like an on-rails hack-n-slash where you also shoot arrows, using a grappling hook and throw Ninja stars. Think if they made a dungeon crawler for Zelda and it was on-rails. That's this game. If it's the right price, I'll pick it up. Fun stuff.
Carnival Nights: Another shovelware title for the Playstation Move, but I'm a sucker for it. The reason? It's like those crappy games you played at Circus Circus as a game where you won tickets and tried to buy fake plastic spider rings and crappy erasers that didn't work. I got to play Skeeball and launch a frog (it's like that game where you hammer the launcher to launch a chicken into a pot). $19.99 (unlikely) would be a must buy price for me.
Resistance 3: I played the Playstation Move version and it was a pretty neat concept, but was lacking some of the freedom of movement I've come to expect from any FPS. Everything was working great except for one part: you have to aim off the screen to turn that way. So if you want to turn left out a door, you use the analog stick to move forward and then aim off the screen to the left to actually turn that way. Not a fan. Also, the sniper gun is a bit on the heavy side for extended play and made me feel really out of shape.
Otomedius Excellent: Take the artist from Sgt. Frog and have him illustrated the ships as women in this Gradius-esque shooter. Fun if you like Gradius. Not if you don't. I liked the customization they gave you for the upgrade path allowed, but didn't give you a good idea of what doesn't work outside of you trying and failing.
Things I Saw (worth mentioning)
Nintendo Wii U: It's neat, but I'm not sure how practical it is. The Wii was great because of both the ingenuity with the controller as well as how easy it was to use. This was has a controller that makes it feel like you're playing with an Etch-N-Sketch. I think the controller itself is really neat, having the touchscreen and camera, allowing you to play without the TV actually being on. My main gripe is just that the main controller is just... too big. I'll have to see if I can get in line to try it out tomorrow for a better feel. It's definitely cool, but not a "I must have this thing".
Super Mario 3DS: It's a nice platformer with a stripped down look. What I mean is that it reminds me of the earlier levels in Mario 3 with the opaque, solid colored blocks (sans corner screws) and just charming in its simplicity. My main gripe, watching a player fall in pits over and over, is that some of the views are obscured and you end up falling in pits... over and over. Other times, when it works, the camera pulls out and you have no problem seeing what's going on.
I don't remember much else. I'm pretty tired.
Related Link: E3 2011 - Day 1 Flickr Stream