A couple of minors issues that take away from the gameplay of an otherwise decent game:
1. Lack of variety - I think there's all of two creature types, the bees and the spiked spiders through the first three levels. I didn't get much further than that because of issue #2.
2. Maneuverability. There's a huge emphasis in this game on floating over things or dying when you fall. The problem in that is there's really not a lot of control in how you move when you're floating, so it's very easy to run into things unless you spend a lot of time honing your control skills. If this were a more involved game rather than an obstacle course, that wouldn't be too bad a thing.
3. As for the things you can or can't attack, the mechanism is odd, but I didn't dock you for it as I'm not sure it's unintentional. I've run into the spiked spiders a few times, not dying from it, but clearly registered in the little noise it makes from hitting things. Not sure that's a bug or intentional.