Amniotic is a good take on a classic form, and keeps up a solid tempo as you progress. Solid, but nothing crazy here.
The gameplay of Amniotic is more remeniscent of classics like Space Invaders in that it is not a side-scroller, but rather the action all takes place within a ring or circle, which is presented as a bodily cell of sorts. Amoebas and company emerge to destroy you, but you can destroy them all by steering into a glowing orb which explodes, eliminating all of the enemies nearby. You'll do this repeatedly and the trigger mechanism does a nice job of keeping the pace fairly frenetic, moving quickly. So the game isn't a problem until the "boss" arrives. These guys are badass. The first one is a sort of eel or snake amoeba and it's hard to kill, believe me.
While the graphics suit the gameplay, they're nothing to write home about. Not that they're bad - far from it. I do think the best thing this game has going is the tempo. It's fast paces, but not in such a way as to make you feel out of control. It's this sort of balance that really hits home and makes the game enjoyable to play and interesting as a game experience.