I got a Amoeba boss in an evergreen forest guarding a resource and I have to say the floating islands made the fight many many times more interesting than it would have been otherwise.
Since the amoeba shots go so far and curve around obstacles a bit I had to platform all the way to the other side of the area where the amoeba was floating around while trying to dodge the blobs snaking their way between and around the platforms. The amoeba was floating around a bit and changing the trajectories a bit so the areas the blobs were passing through kept shifting along with "safe" spots. Meanwhile the monster spawners were pumping out bats. I had to fight off bats while jumping platform to platform while dodging the blue blobs coming through the gaps between platforms.
The only thing that was kind of a let down was that when I finally got close enough for a clear shot the amoeba got itself stuck in a corner and made for an easy kill.
Seriously, I think rooms for amoeba bosses should have solid floating platforms to for the shots to curve around and for the player to take cover behind. I think it would make for a much more interesting fight as long as the amoeba doesn't get itself stuck.