Into The Expanse
I felt that the percussion was a bit too much and fought for attention with the lead line for me, maybe having it build in intensity/instruments towards the end would be better? Might just be my personal taste, but the constant kick and snare drum duo got a bit too much for me since it starts early in the track, and was thinking that maybe just having the snare drum playing some accenting stuff with the bass drum being used more sparely until nearer the end would have give more power to the whole big crescendo feeling of the track.
Echoes In Space
The synths, guitar and celeste combo was great, maybe having some other contrasting instruments to the guitar and celesta with their own b section might've been cool to help keep things not sounding too samey/boring, since the whole 3 minutes of the track is just the guitar and celeste.
Cosmic Storm
The vibe and sense of urgency on this was really nice,
Discovering The Unknown
Talking from a listening experience viewpoint, when listening to the tracks in order I felt that this could've been more bombastic to really feel like a grand finale to evoke that Discovering something new feel, especially since at least for me, the first track felt more powerful.
Just some very personal opinions and feels I got while listening, but still, good stuff!