Fun
Graphics: Well done, nice color scheme, well-achieved 8-bit style. Looked very retro but still somehow natural. Really well done. It was really cool how the fish pulsed to the beat, and the cool grayscale effect when it was paused.
Sound: Good quality, very good music. I've left a review for the song featured in the game if you want to know more about it. I really didn't like how the music stopped if you crashed into something, though. I know the whole point was to sync the level with the song, but it would have been better if you had just lost a life instead. I noticed myself jamming to the music only to have it stop when i blindsided something. It was pretty well synced, though.
Gameplay: Pretty sweet. I liked how you could lay eggs, since it's a strange feature to be able to choose when you save your game. However, it was pretty tricky at times, in that hard-stupid way as opposed to hard-fun. Not only that, but you got infinite lives if you lay an egg right before an extra egg pop-up. It was too hard and too easy at the same time, which really ticked me off. While it was fun dodging stuff to a beat, the bats in the cave really annoyed me, as it seemed their placement was random. Irking, since you couldn't do too much about it. It would have also been nice if you could see a layout of the level before trying it. This would have given an underdog player a lasting chance at first go, which really gives players new to the game a thrill when they think they might win. Speaking of new players, it got obnoxious that every time you died you had to watch the death animation. Sure it was pretty short, but it got on my nerves sometimes. Most players want to lash back at the level like a dying snake (albeit a rather stupid one), so that should definitely be fixed. I also didn't like how it didn't tell you how to beat the boss, and that if you died during it, you had to restart the 3rd level in addition, since I've redone it so many times I could do it with my eyes closed. And, like a lot of players, I agree that the controls weren't too hot. The fish slid around a lot, and although I enjoy games with sliding (like Fishy), it got obnoxious that I had to use imprecise controls inside of a very precise environment (eg. to music, to a beat, etc.). Perhaps the easing could have been downed a little. The achievements were pretty unpredictable, too. I'd look at one and wonder if they really tested your skills or if it just rewarded someone who was curious (or dumb) enough to try something out.
One of the better rhythm games, but lots of room for improvement.