Thanks for the feedback. Actually, the idea is to get the data for the ghost player not from the local storage but from the server, where people can upload their score and their run's data. Then, the game will pick a run that is slightly better than the best local one and use that for the ghost player. It's a kind of delayed multiplayer...i just haven't implemented that right now and i'm not really sure if the ghost player is prominent enough to make this work. Maybe a simple highscore would do the same trick...!?
Cool idea! A combination of high-scores and this 'delayed multiplayer' could be very cool too: You always race against the person 1 place higher on the score board to get his position.
About controls for the speed: I decided against this after playing (or trying to play) a lot of Android games. IMHO, most of them just suck because of the controls. The only games that i liked were games that could be controlled by one touch or a few buttons without having to shake or twist the phone.
In HyperBlazer I used tilt for speed (and it's implemented not as analogue controls, but the tilt speed controls act like 'binary' buttons), and I thought that worked quite well. Of course most of the time you just try to go as fast as possible, so actually you use it just as a break in practice.
I agree that the levels aren't really unique (apart from the graphics) in what skills they demand from the player. I don't think that this is necessarily bad...if you look at some old school racing games from the 8bit era, it's not different..colors and graphics are changing and maybe more obstacles apear on the road but apart from that, nothing really new is added to the mix...just plain racing. But you definitely have a point, i'll think about it some more...
Your game has actually quite some similarities with HyperBlazer/Trailblazer, and I think there is still quite some variety in the levels in there. Well, I tried to put some thought in it
What I tried to do for example is introduce the different kinds of tiles/obstacles/holes etc gradually. For example the tiles that reverse the controls come at level 4 or so, a level later come tiles that explode, then the tiles that makes everything turn around come even later, and elevated tiles come at the final stage where it almost becomes kind of like a platform/racer kind of game. And in some levels, some the focus is on some specific combinations of tiles that require a bit of a different tactic. That gives some sense of progression and achievement.
Perhaps your game could use a few more different kinds of obstacles and bonuses too. And I really believe some kind of speed control could help adding more depth to the gameplay.
I'm not trying to suggest you should make it more like HyperBlazer though (I'm sure you're able to make it much better than that, and it already looks a lot better :-)), just trying to vent some ideas.