Love the visual style, the polish, the music, looks super professional and I can tell the work and love that has gone into it! Some honest feedback though - after 30 mins I started feeling a bit bored. And I believe the reason is that I didn't feel that as a player in the actual level, you have many (/any) interesting choices to make. You just watch what happens play out - or shoot things with sky bolt if you're using it. That's not fun - just waiting for X minutes to get the gold at the end.
I'd suggest thinking of ways you can make the game more interactive without adding too much work. Maybe you could switch between evolutions or loadouts on the fly or seomthing?
The one thing I'd say about the metagame too is that on the previous The Last Spire there were a few choices / avenues available to the player with what to choose to spend money on. With what's available in the demo, it feels like the choice is "spend the money on the most OP spell right now, or waste it". Maybe a little bit more balancing, combined with the spells being interactive in-game in some way and therefore matter more, could make the choice of metagame feel more meaningful.
Just my thoughts!