Loved this game for the first 30 minutes, and then there seemed to be no more checkpoints and the only way to climb one section was on the side of the sun... which meant restarting from the same checkpoint 10 minutes back about 10 times... at which point I gave up and uninstalled it.
Shame, as the first 30 minutes was great, and the checkpoints for that section seemed fine.
It'd be better without the sun imho.