Gonna give feedback track by track.
Intro: I like the feel of this. I also like the use of the voice clip. I like your flow, but sometimes it feels like you're rushing to keep up with the beat instead of flowing with it. That leads to slurring and some words getting lost.
Undefeatable: I like the BEAT a lot. The hook is kinda meh, but the beat is great. Was a little thrown off by the producer tag. The producer tags kinda bring the production quality down a little. Flow was a lot better on this, but it still sounded like you had a hard time keeping up sometimes.
Not So Gorgeous: The beat on this is great too. On singing: If you can't do it well enough, I'd not do it at all. Not saying it was horrible, but it was VERY Eminem in terms of just singing even though it's not really what he does. I'd blend the featured artist's entrance a bit more, too. He comes in VERY suddenly, and it's kinda jarring. It also sounds like the beat gets louder once his verse finishes?
Dance With Me: I like this song. The problems I've mentioned earlier are pretty under control this time. It's just the times the beat switches from rap to the hook, it's a huge switch, and it doesn't really seem right. If you can, I'd find a better way for it to come in.
Left Brain, Right Brain: Love the title and the beat. When you change your flow to the faster bit, it's seems kind of inconsistent on what kind of rhythm you're trying to follow. Also, if you're gonna rap fast, make sure you can enunciate well enough. If you don't, the words get lost, and the impressive-ness of speed means nothing if that happens.
Let Me Down: I feel like I've heard this beat before. I like your rhythm on this. It's very cool, and you keep up fine. There are some times it just feels like your verses are cut short for the instrumental break, but that might be a fault of the beat and not you.
Sparring Session: The beat of this is GREAT. Also, this might me my favorite track in the whole thing so far. Your rhythm is great, the lyrics are good, and the whole thing just sounds great. Mixing wise, which is where I've have the most problems, I didn't have anything to say for this one.
Beyond Limitless: Beat is cool, flow is better than most of the other songs, and your rhyme scheme stands out on this one a bit more than on the other ones. I think this is a pretty good track to close the album with.
Overall Thoughts: Mixing needs a little work. Mainly just lead-ins, cut-offs, and blending your vocals a bit more. Most of the time it sounded like the vocals and the backtrack were two separate tracks. And while they SHOULD be, it shouldn't SOUND like they are. They should come together as a singular unit. Overall, this was good. Lyrics were good, beats were great, everything was pretty decent.
Keep at it!