This was a lot of fun! I agree that it's a missed opportunity for a nice explanation of the Collatz Conjecture, which I would've enjoyed (and I assume you would've too!) But I enjoyed the level design and gameplay a lot. I noticed a couple of things: when zoomed all the way out, the guideline was very small and hard to see. Also, at very high speeds, the velocity can get stuck 100% vertical or 100% horizontal, which won't ever hit the hole and beat the level. These issues didn't stop me by playing the game as intended, which was really fun!