I really had a hard time following the majority of this song. The key changes sounded like they were all over the place in the first half. I didn't hear much on the end of transitional phrases, they just kind of droped you off with a new segment. A simple remedy is to place something a measure before a shift happens to let the listener feel that something is about to happen. Be it reverse snare, drum roll, vacant kicks etc.I couldn't tell if the kick was peaking at times or if it was the sound of the kick with that 16 bit sound to it. ( leaving that out)I am uncertain if the linux program you are using is compatible with vst's. However if i recall i believe it is, I would suggest getting Native instruments massive to make your synths in. Some others you might want to look into would me sylenth1, Zebra , Dune, ReFx nexus, z3ta2.
I also noticed that the kick drum vanishes when other sounds come in, that problem is due to mixing. Make sure your chans arent peaking, give them at very least -3 db room to master with. You never want each channel to hit its db cap then add another sound in.
Over all however its pretty good for what it is. It reminded me allot of mother load music at times. I was having a nostalgia trip in some parts lol.