Pretty impressive that you guys are doing your own engine and submitting a project with it. Definitely looks good.
Tbh though, I don't see it as a "game" much, more like a tech demo, so I can't comment much on the gameplay aspect of it. The physics is kinda funny, I don't know how you achieved that.
Very nice visual effects, even though it's just cubes. Like the other commenters have said, the controls feel too hard to use so most of the time I don't know what's happening around me.
Very cool it's a custom engine though. Excited to see where you go next with this.