Thanks a lot for playing my game and for your feedbacks! (Also, as I say everywhere I'm French, so sorry if my english is bad)
I know for the "one-line" technique and the graphics of the enemies, that look really similar.
At the beginning, I wanted the ennemies to shoot (the 2-hp are literally called "EnemyShoot" in my code) but I don't know why it didn't worked, so I just made them "more difficult to kill".
I also wanted to add moving enemies or something like this so you have to move to kill them, but I didn't have time (and talent) to make things like that. I prefered make little but good (as you can see with all the little feedbacks and the portal, that took me quite a lot of time) (You can see that I uploaded the game 1 day before the deadline but the last day I had school so I couldn't do anything)
I thought at the beginning, that it would be cool that the more you're taking speed, the more you just avoid the enemies and totally ignore killing them.
Also for more technicals things like the music speeding up (which I thought could be cool), I just don't know how to make it ^^
However, the thing I didn't even thought of was the collectibles. The fuel mechanic is a really great and simple idea.
I hope I'll continue this project and make it better, but I'm sure I'll participate in other game jams!