I haven't seen you post in a while. The premise is still great and you've done a really good job with the movement.
It would be nice if the ATV landed on something it would just kill it. I assume enemy death animations will eventually be added as well.
Also is there any reason as to why items don't just get automatically picked up. I feel like the key could be it's own thing. If the reason is that you want control over the pickup is to remove the ability to accidently replace an item you don't want, i feel like this is something that is better solved with level design rather than system design. The easier this game is to play the better, i'm a bear on an ATV i don't want to think too hard.