That was really nice. I really enjoyed the multiple mini game format; the surprising context switch the first time you see each one is pretty cool. I really enjoyed the presentation too, with the start screen and the little intro cutscene. You can feel a ton of design work in every scene, from the font designs to the way the sprites interact with each other in the water. Top notch stuff.
I sort of wish you had gone for a more colorful palette though. This monochrome one demonstrates a heck of a lot of skill, but it just leaves me wondering what it would look like with more hue contrast.