good effort. also just to be sure on the terms you use, mastering is not going to change sounds you use, just minor things in the overall tone and volume.
The sounds glue together nicely, but there is something indeed in the tone, maybe it's focused too much on the high frequencies. The blip melody is way cheesey. And yeah the drums could use some dirt in them, instead of the synths and bass. Sounding clean is ok but this is a bit much.
I'd really recommend some tutorials and preset mangling, and I do say that with respect.