Cool little game. Here's some feedback based on some notes I took while playing:
Could use controller support, and ideally button remapping but there's not a lot of different actions in this game. But considering this game is built for speedrunning, letting players play in the way that they find comfortable should be a high priority.
The music restarting whenever you retry a level would get grating, again since there's this clear emphasis on speedrunning that seems like an oversight.
It's not so great that you always can't see the platform you're trying to land on so sometimes I had to blindly jump in a direction and hope there was a platform there.
The controls were good and I liked it despite having to play on a keyboard, I feel like there were tricks that could improve my time that I have not yet discovered and if this game got another pass of polish or some extra levels I could see myself coming back to this.
Edit: I just read that this was made in a week as a self imposed challenge, so I'd like to mention that I did not take this into account when writing the above critiques.