Composition in Q is absolutely perfect. The beginning of the Tyrian theme is absolutely amazing, but the second half goes downhill somewhat. Rock Garden is.... not great. Most of the songs are a mixed bag, with many parts clearly superior to the original. However, most songs feel somewhat empty as well and as a percussionist I disagree with a lot of the sound fonts that were used for percussion instruments. Overall, I think there needs to be more low end (bass drum, bass guitar, etc), a bit less reverb, and some of the more lively tracks are just crying out for a solid dance beat.
Good job though, and keep up the good work! Don't be afraid to actually add to the tracks too!
If you're open to constructive criticism, I'd say you can safely double the volume of the snare drum, same goes for the bass drum drum, and use a more high pitched ("pingy" even) sound font for the ride. And it would be great if the first guitar had more of an electric guitar feel to it like in the original.