Some really cool vibes in here, and the production quality is great - really does the tracks justice!
Mosaic has a slow but effective build before it starts to really get into itself. Great choice of synth patches here - big fan of simple waves being used to lead, accent and add some ear candy á la the squares used. Nice articulations with some of the pitch bends and portmanteau. Percussion was straight-forward but just what the track needed to keep driving forward.
Aquamarine does a great job of setting the stage off the bat - the filtered pad and soft mallet-sounding melody makes me feel as though I'm floating underwater. The addition of more synth layers accenting the melody does a great job of fleshing out the mix without busying it too much, and the choice of keeping the percussion rhythms to just the likes of hihats was clever - I don't think a track like this needs a defined kick or snare to set the rhythm, in fact I feel as though it would actually take from the floating vibes if it was grounded in a beat.
Cold Star taps into the same kind of feelings as Aquamarine. Great choice of patches here again and a lot of bendy goodness with that background melody - something I think a lot of people are afraid to really put to use. The lead synths in this do a great job of complementing the background textures and the prevalence of an actual drum beat in this does a nice job of providing the track a core heartbeat to keep it ticking along. Would've loved if this went on a little longer!
All in all, super solid work. Each track is unique but as a whole they're very cohesive and fit well together. Could imagine this in a couple of different types of games. Great work, and best of luck!