I really enjoyed the bullet heaven/hell feel of this one! I love the control explanation window, I thought that was a nice way to give me time to learn them. The sounds and visuals were all top notch. I especially like the cracking glass.
I only have some nitpicky things: I played for a while and felt like there was something else to do. I never did get the train to move, any weapons to swap, or what not. So mainly confusion on how to progress. If this is coming in waves, maybe show me a timer for when the wave will be done? or highlight the thing I'm supposed to do or collect.
I was able to get tons and tons of new mechs, but I had no idea how many were standing on top of each other.