Well, I've played through both of them, and I actually like the first one a lot. Sure, it could use some polishing here and there, and it's a little too short, but overall it was pretty fun to play.
The second one is... uhh... premature, to say the least. 32 of the bricks don't load, and after you've reached the entrance of noobland, you come to a dead end with no apparent way to continue. I had to cheat my way to Red Raceway, and after driving through it I was stuck again. I assume that it was the end, but there was no way I could tell.
In short, the first one was good, and the second one was crap.