Nice game, I enjoyed playing through it.
I really liked that you didn't just limit the game to a physics simulation ball game, but included situations which forced me to think about what to do next. I also really liked the underwater mechanic, and especially how well it played with the situations I mentioned. Well done, it's well-designed!
A couple criticisms:
- Half of the time, you can't really tell where the ball is going. Partially because the bat speed is a little bit too slow/delayed, and because you don't have an indicator telling you about the ball's arc, etc. The latter is fine because I understand it may be up to personal preference/game jam, however. The former impacted the experience a bit for me. I did not always feel in control of the ball.
- The music can get pretty repetitive. It's an ok piece, though.
PS: the game can be a bit too hard, with the spikes, too. But, that may be up to personal preference/the sometimes difficult control of the ball.
Overall, a nice entry. Good job.