Loved the metal vibe to the idea. Excellent vocals on the last track and the second track went so hard. I love this type of sound and think you did an awesome job.
My favorite is actually the first one! I think it sets the tone really well and I had a solid understanding for what to expect in the others. Incorporating the theme into the lyrics at the end was also a nice touch that resonated with me too. We did a similar idea to have the last track a full song, but our implementation was totally different. I love that comparison and seeing stuff like this is why I love doing these jams. Great work!