The node based upgrade system it's very interesting and fun to fiddle with! I think the game it's really fun, although I think you could make it a bit faster from the start (enemies and attacks be a bit faster)
I didn't really saw how this one fits into the metroidvania genre though, which would be my biggest complain about it. But ignoring that it's a very solid game with very good potential.
Viewing post in Gods Penumbra jam comments
I must admit that the metroidvania elements are not obvious at all, since there are no typical metroidvania elements on the map. But you could theoretically defeat the bosses not in the main order, unlocking certain parts on the node board much earlier + the unique nodes are are meant to represent new abilities.