-Shitty frame rate
-Feels too chaotic at times, especially when you have a bunch of karts on the screen with the frame rate dipping
-Drifting felt kind of weird (with Sonic)
+Tricking to get speed boosts when landing is nice
+Looks like a nice selection of tracks will be available
+Frame rate aside, visuals are nice
-The announcer sucks
+Plenty of kooky items to use
-Character-specific power-up items seem overpowered and unfair
I read Darth Sol (a Sumo Digital employee who usually is on GameFAQs) has said the frame rate is an issue with the demo and will be cleaned up by the time the game comes out. After playing it, however, I'm certainly not going to be picking this up at launch. (Not that I was planning to, anyway)