Crossing the Divide – I think that indistinct language use in video game music is a super cool technique that adds an element of other-worldliness or fantasy to music. I am a fan of the bouncy major chords and I like the progression you used a lot. This is probably my favorite of the 4!
Teleportation – This has a taste of Metroid to it. I like the spaciness you used and the vamp between the two adjacent major chords. The female vocal soaring in the background is a very nice touch!
Abyss – Great use of pitched percussion here. This is reminiscent of classic factory or machinery-type levels and I enjoy the use of bass drum with the buzzing electronic sounds together to create an interesting groove.
Other World – This change in pace and flavor/style really rounds out your OST while using common elements that make it feel cohesive. Overall, this is a great OST and an impressive amount of different music to have made in the short time-frame. Thank you for sharing!