This is *amazing*. I defeated the first immortal playing at night. I really like the idea of the dark piledriver, instead of just being forced to play the game during the day to beat them.
The style of the game is impeccable. It brings me straight back to the Boktai games in all the best ways. It also feels like you brought in the best elements of Lunar Knights without any of the garbage.
The writing is great, I love the chemistry between the two main characters, and I love how sassy and pompous Emil is about Annie's brashness.
Really, I'm just happy to find out someone else loves this series as much as I do, enough to try to make a game based on it. I'm writing a tabletop RPG ruleset in a similar vein!