I'm just going to say this piece based on what I read.
1. A story-based metroidvania? Are you mad? A couple of dialogues is fine, like in the later Castlevanias, but completely story-based is going to heavily mar the exploration factor of the game. That's enough to push me away in a major way. You can't really competently structure a story-based game and have it also be nonlinear or have too many branching paths. Either the gameplay or the story will suffer as a result. Judging by the fact that he's worked on Monster Tale, it's probably going to be the gameplay that suffers.
2. The actual gameplay doesn't really look deep or impressive. Metroid games give you a lot of tools and cool weapons and dangerous native enemies. Castlevania games give you a lot of RPG elements, spells, and weapons. This looks like a game where the stakes can't really get higher from where they begin. Super Metroid has you move from Zoomers to almost-invulnerable Space Pirates as you move from fairly strong to almost invulnerable. Castlevania games give you glyphs to combine in countless ways (Ecclesia) or allow you to steal enemy attacks outright (Sorrow). What sets this game apart? It looks like you have to wander from waypoint to waypoint just to watch each cutscene and get the slide/double jump/screw attack/energy tank, same as every other metroidvania.
I'm not impressed, frankly. Maybe I'll play the demo, but I don't even feel like spending my time on that. I've played almost every metroidvania there is, and this is the only one that I haven't seen any kind of unique mechanic or major difference. Pretty sprites isn't enough for me.
Edit: I will amend point 2. It has a combo system going for it, but that looks like all. Unfortunately, again, that's been done more than enough in this genre anyway. It's not like it, say, contributes to your score or anything, so there's not much reason to do it aside from feeling cool. Monster Tale did it, as did Fortune Summoners. Fortune Summoners actually practically made the combo system mandatory, because the combat was incredibly hard. You had to keep enemies locked down or you were basically dead. Monster Tale gave you more materials for combos. Doesn't look like there's any incentive here.
