I've never heard of a 2-player co-op metroidvania before! I was pleasantly surprised how well the online play worked. This was definitely fun to play with two of us. I'm not sure if I would play this game one-player. I was gripped because I COULD play it with a friend and it's in a genre we don't ever get to do that in.

That said, when you're fighting bosses, it is VERY clear that the 2-player feature was added in a later update. Many of the bosses are not designed for two players at the same time, as in, broken in the boss's favour. Lots of hits you're taking that would be avoidable in 1-player but not in 2-player, usually leading to a game over. That said, the two of us did get through it in the end, it just felt like we had to exploit to win.

This is only a problem with the bosses, and even then not every boss. Every other part of the game was well-designed for co-operative play. You can explore the map together to help each other out, you can split up, you can teleport to each other, and you MUST revive each other if killed.

It's a very decent Metroidvania, simple and straightforward.

I don't have anything to add; it's definitely enjoyable.

Awesome co-op game.