This game suffers from a fundamental flaw and that is that in a racing game you don't really wanna be near another opponent, I guess it can be fun with a lot more people but the range for getting the abilities is so short that I don't think it really matters the number of people if you get a bit stuck behind just by a bit you are already losing all the boosts, the idea is creative but I don't think is handled well, also the music didn't seem to work in the game, it would sound for a bit after beating the level but afterwards it was complete silence.
For the online though, we had a few problems at the start but once we could play online it worked perfectly, no lag, no conexion errors nor random disconnects and for an online game made in a week thats amazing.
Overall I like the idea but I don't think the sticking together in a race is a good design.