a good bash! I like the Idea and serenity does give off the right vibe for it, so you hit the brief pretty well. I will also second mr Society Man and say the call and response is a nice technique which was used well.
In terms of critique: As you say the production is a bit lacking but I can't blame you for that - DAWs can be pricey. In terms of composition I think there could be a bit more space for the melody to sink in, particularly the first minute of 'serenity' is quite continuous. Serenity also has room to be slowed down a bit or have some tempo stretching, it's serene init, peaceful. I also think that you could do with a bit more on the percussion side, especially in 'tension'. percussion I find can really lift the energy of a piece.
Overall, good effort! Keep at it!