Nice little game you've made. The gameplay is simple but you still managed to made it fun. I don't fully understand how the grapple is intended to be used, but I still had fun upgrading my speed and ramming into stuff. The main thing I think that is lacking would be progression. The upgrades did not change really change how I played the game and I ended up staying in the same main square every run. Having some hidden areas that requires certain upgrades to reach (and reward the player for doing so) would be a cool addition. It would also be nice to have a countdown towards the end of each run.
All in all, great submission and good job on it!