Allow me to brown townyze this.
Hopefully, they've improved upon synching the music to the track, as the first was more like listening to music while running into blocks.
The effects are too much, almost blinding. Especially after crashing down from a jump.
I don't like that they are trying to enforce the idea that you are surfing on music. No need to look like I'm waterboarding (since you are clearly connected to two balls on the edges of the track pulling you along. clearly not actual surfing).
The tricks I don't necessarily agree with, but after all, this IS a score attack game, and the tricks are purely for points. The jump is way too high, and that was probably the point, but it separates the player from the track (you know, where the skill is required and the things you actually have to dodge and collect are), and whereas in Audiosurf you actually had to try and show effort to get a lot of points, in Audiosurf Air you just need to get that BIG AIR and wrack up all the motherforgetin points.
As for the speed after landing, we have no idea how that will be affected depending on what difficulty you choose - just wait to see how this turns out. (also, the player jumped by hitting the waterline on the edges of the track, as if it were real waterboarding)
Also, when you hit a block the block is sent forward a bit before vanishing. That got a bit disorienting for me when there were multiple blocks in a row.
Audiosurf had this unrealistic, high-tech feel where you were piloting a sort of spaceship or hovercar through a song, but Audiosurf Air seems like it's aiming for a more semi-realistic feel that isn't supposed to be there. It's almost unnatural.
Bottom line, this is a possible buy if the effects are toned down and some of the cons mentioned are fixed or adjusted. Previous Audiosurf fans will probably like it, but the huge differences between the two games could potentially turn a lot of old time fans and newcomers alike away.