This is a really good game, I really liked the game.
I have a few suggestions for the "exposure drains strength" Instead of us taking damage change the "plants or moss" from green to brown as to signify that we are damaging the plant/moss
I really want to drive a motocross bike here. If you are making it into a "big game" my suggestion is to make a really big map with little puzzles so you can look at their progress