Not bad
Found 2 bugs.
1) I beat the first level on my first try, bought 1 seed, and continued. beat the second level, and then when I go into upgrades, it just gets stuck and the fish with the bone screen. Problem resolved by ignoring it and not buying upgrades at that level. Other level upgrades are fine.
2) My firefox crashed sometime during this (not your games fault) but the autosave seems to have gone funny. I was at least past the point where it needed 17 L of blood to get to next level but when i pressed continue, Im back at the point where I beat the first level and nothing else.
Others: seeds move kinda funny, you can still eat people who fell out of the screen if you have lots of seeds by running around on the bottom, sometimes people swim into the air and swim up where we cant get them.