Really interesting concept, but I wish there was more to it, maybe an upgrade system could make it more interesting to play or some kind of addition to the train like adding turrets. Talking about the train, that 3d model is amazing, I love the design. Same goes for the mech as well!
Only major issues I had was the sound. Music doesn't loop and the sound changes depending on the rotation of your character which is pretty irritating to deal with.
But fun concept overall!