First of all, huge congratulations on the 2D animations, they're incredibly well done! The animation quality is excellent, and the timing of each frame matches the hit feedback perfectly, making every punch feel really satisfying.
The only thing I probably would have added is a twist to the core boxing gameplay, perhaps something tied to the Countdown theme to make it feel a bit more unique.
Overall, it's a simple game, but it's executed really well, especially considering it was made during such a short game jam. Great job!