I feel like there should be some additional threats to knock you over, and risk-reward items to encourage movement, jumping, and tricks. The safest and most obvious strategy is just to stand pretty still upright indefinitely, which isn't too difficult. I feel like a pseudo-infinite score could be gathered just by more-or-less standing still (maybe jumping straight up and down) which is boring. Don't let players optimize the fun out of your game in its design.

There could be rolling rocks or roving lunar rovers or aliens or something on the ground that will knock you off-balance and over, so you have to jump over them. There could be a point-system for tricks, but that's harder to make and very hard to balance, so perhaps certain colored stars would try to dodge you so you'd have to rotate down really fast to catch them, or something along those lines. Anything to force/encourage the player to play less safely.