Whoooa, lots is happening here! lol
I had NO idea you made music! I can hear a lot of improvement from Stretchy to this one here, but there are still some things that could use some touching up. As Alka said in his review, there isn't really a main melody that people can follow along with, but really it isn't a bad start at all.
I can tell that you're trying to lean towards the styles of the songs that you use in your levels, and I definitely appreciate that. We need more songs like those. The only downside is that those songs can be pretty difficult to make, depending on how complex they are. Something like Ramen Carnage is a product that would take a LOT of practice to come up with.
Make sure you're making your variation prominent and noticeable, but also not to a point where it compromises the song's integrity. EQing your sounds and making sure instruments aren't overpowering other instruments is also really important. The song stays consistent with its mood, but it's never a bad thing to let it move a little bit. Think of a song as a story; it's supposed to go from point A to point B. :)
Also, there are a lot of presets and stuff online that I would recommend looking for. One of the problems with most DAWs (DAWs being programs like FL Studio, Ableton Live, Auxy, Reaper, etc.) is that there are never enough sounds that you can choose from. Plugins are a great way to optimize and diversify your sounds as well. It's always nice to have an arsenal of them at your side just in case. ;)
I'm definitely not the most informed person to ask, but if you need any help with this kind of stuff, let me know. ;p