practically unplayable.
when i first played the game, the first 15 seconds posed little problem to me because of the relatively few obstacles. however, the difficulty increased sharply immediately after as i had to jump over more obstacles within a short distance along the way. at times, it is impossible not to slow down. being caught by the avalanche within seconds in inevitable at that point, no matter how precise i made the jumps. there seemed to be a limiting factor to how far you can travel in this case.
introducing upgrades is a good idea. one possible suggestion is to reward players when they make a series of perfect jumps. people should be able to pick up a few overrunitems (for example rockets to make you airborne, or device that can slow the avalanche). this makes it more plausible to overrun the avalanches and reach a certain destination.
graphics are alright for a mini game like this. the black and white colour helps create a eerie feeling. medals are either too easy or too hard to earn though. i unlocked the first few medals without even knowing what has to be done to unlock them. on the other hand, i never 'entered the lair bones', despite getting a score of 13,000 after a dozen of retries. perhaps you should reduce the distance required to earn that medal. same for the remaing ones.