The lead instrument is very nice, and catchy. I also really like the tempo adjustment. And the way you bring in the sound for the drums is really cool; starting with the 8-bit sound and bringing the hard drums over it. The new instrument at 0:52 fits perfectly and the timing for it is great.
One thing I noticed though, is the lead doesn't seem to stop. Even at 1:29 when the sound completely changes, the lead still continues. It starts to become boring hearing the same sound over and over.
2:29 is good, and I like the sounds panning. Throughout the song, you have that trance sound (I don't know what it's called) where you bring the sound in and out, like it's being compressed and decompressed. I like that a lot, as it fits the track.
The ending is good, but I would either end it at 3:44, or let the lead finish it's riff, as it would make the whole song loop perfectly, and might not sound like it's cutting off so much.
Overall, great track. Despite some minor flaws, you still get my download and a 9/10, 5/5 from me.
Overall, pretty solid. I didn't think it cut short at the end, but there's a pretty dramatic tempo shift on the loop that could be cleaned up better. Also, I don't think the basic melody is catchy enough to play for almost the entire track. I mean, it's fine as is, but I'd either mix it up a little or bring it in and out a little more. Good job. :)
Please contact me if you would like to use this in a project. We can discuss the details.