I liked your music track - it was nice! Some of the SFX around it were distracting because they were lower in quality. The water drops sound needs more of a tail on the reverb. A cave has more echo and depth than what I'm hearing.
Our game is about a bird born in a cave, so creating realistic sounds of a bird walking, flying and landing has been the most challenging thing for me. If you have any tips at all, I'd love to hear them.
Depending on your budget and your intentions, an a la carte website might really help you find some of those hard-to-record sounds. Something like Sound Dogs or Sound Rangers or even Pond 5 could work well. If you're wanting to create everything yourself and not use any 3rd party materials, then this thread has some good info which can get you started: http://www.gamedev.net/topic/523411-creating-sfx/