The first part was solid, but the second part was outstanding. The main theme was really good, and the boss attack pattern was super satisfying. I would’ve loved to see a health bar for the boss like in The Binding of Isaac, and maybe have the portal in the first phase also have health — with a break between waves, where if you destroy it, an even more powerful one appears with different enemies or new attack patterns.
But for a one-week jam, it was excellent, and it’s definitely a game that can be expanded even further into new mechanics or areas.
Great job!