I really appreciate the kind words - and I'm super glad you liked the game!
We were going to have the other players who are on the leaderboard show up in the game as enemies that are spawned in when you pass their highscore, giving the illusion of you actually racing them. Then we'd have a bar showing you your position on the leaderboard, and you would CLIMB your way up - knocking the other people off when you "passed" them. That was the whole climbing thing, but we didn't get to add it in in time! Making the whole theme basically non-existent. Lesson learned about scope creep, I guess.
The more damaged your car is, the more harder it is to drive. The wheels on your car make up your speed, the suspension is how fast you can use W and S to move up and down, the more your "steering wheel" is damaged in the indicator is how limited your boost is when it comes to overheating, etc. The engine is simply a health bar that explodes if it takes too much damage. They all have effects excluding the last one, but I guess that just goes to show that we need to make their influence more obvious!
The upgrades are really hard to get by design. It's not a matter of "get gud" as much as it's "haha, please die quickly so that you don't get bored of the game and live forever." since the game IS a little repetitive with only one enemy and one goal, which is a highscore.
Once again, I really appreciate you playing our game. <3