Sounds pretty good to me. I would suggest working on the snare drum, sounds pretty flat. All of the riffs lead into each other nicely. Don't worry about length, do what feels right. If it feels like it should go on longer to you, add more to it but don't write stuff just because you feel you need to make the song longer.

If you get a chance, check out my song :
Really nice intro guitar lick! Sometimes, I thought some vocals could add to this tune. Does your neighbor Martha Stewart sing? The ending is a bit abrupt. If it's going to stay an instrumental I'd probably make it about 30 seconds shorter, but that's just my opinion. Playing is tight. Sounds quite good overall. Please review my music at this link:

Excellent quality. From the second the track starts playing, you can definitely tell this is one to pay close attention to. Great riffs, nice guitar tone, everything sounds awesome. I think the drums could have used some heavier double bass in parts though. In my wn opinion, I would keep the track around the 3 minute mark. It sounds great so far. Sick lead playing. Vocals would do this track good. Ends too abrupt for my taste. I'd carry it out a bit longer. Now I think you should have this around a 3-4 minute mark. Excellent track though.

Crit for crit?