you can turn the sub up higher without losing the drums if you sidechain using a compressor.
The main pad sounds like it could use a chorus and/or stereo enhancer for a little sound quality increase.
The tune automations on the sub/808 thingy seem a little random. try to think of the tuning as a second melody to accompany the first, rather than just a cool wavy thing.
overall this is pretty neat but could definitely use some refining