I'm not going to get into a technical dissection of your recordings. Your request is a broad one, which asks for broad answers.
I like some of the tunes. I hope they are originals.
I applaud your taking a crack at recording a demo yourself, AND then coming here and putting them up for folks like myself to hear. Kudos for that.
I will give you three broad ranges of quality in recordings. These are all subjective, and opinion based:
1- Album ready. Finished product, ready to peddle to whomever may want it. Your best work.
2- Demo quality. Nice, but not the best it could be. Weak or incomplete performance. Not the perfect sound or quality. Fine for promotion, or for giving out to friends.
3- "Learning the songs." Used by everyone to document where you are with the tunes. Allows you to fine tune the details, and get them ready for the next step. This goes for performance as well as sound.
I would agree with Andrew and say that these recordings would fall into the #3 class for me.
Keep recording your songs, and use albums you like as your benchmark, or reference. Work at it and you will get closer to what you like. This is the definition of what is "good". What you like is "good".
It is hard when you are starting to listen to your own work and be critical of it.
BE CRITICAL! Make it sound good to you, and it probably is good.
After all that, on the other hand, if you have specific questions about how to get to where you want, ask and the folks that hang here will be more than happy to help you out, as we disagree with one another...