I could get stuck on the trees on the sides if I went between them and the wall. I also feel the movement was a tad too fast and made it harder to carefully strafe between tight spots.
The slashing while not too much of a challenge was still very satisfying. The variation in enemies was cool. The art was neat, the music was a nice fit.
Very impressive you did this all in C with SDL and 10 days.
Overall a fun experience.