This is a pretty good RPG Maker game - the combat is solid if a little easy late game, and the map design is good especially in the final dungeon. The custom art is excellent and plentiful, the story is reasonably well-written from a technical standpoint, and it's very polished and generally free of major bugs or typos. Overall a pretty enjoyable RPG if you like or can set aside the tone.
That said, the tone's a pretty big thing to set aside, especially since it's an Eroge that chooses to emphasize and occasionally revel in its dark moments rather than handwaving them. The story overall is pretty dark but not (usually) unbearably so, and there are plenty of lighter or more hopeful moments too, especially in the mid-to-late game, which gives the impression that it's leading towards an "earn your happy ending" moment. Unfortunately the final dungeon doesn't deliver on this, whiplashing back so hard it actually surpasses the second chapter's already very dark tone and ends way too abruptly with little-to-no payoff for anything other than the immediate conflict.
The whole point of the true route is the protagonist putting aside her selfish desires to get bad-ended to focus on saving people, but whether you can actually do so in any given case is also wildly inconsistent - I don't want to get into spoilery specifics on the game's main page though, maybe I'll use the email mentioned in the credits. With little indication as to which events or contracts your actions can actually matter in, I often found myself more annoyed with a decision or event I found stupid because in a different (better) contract or sidequest I might have actually had a choice instead of getting railroaded.
Thankfully, the game's still in development, although the focus is currently on fleshing out the vampire route, so I have hope that the ending may eventually get expanded and that some of the plot and tone inconsistencies can get smoothed out. Even with these issues, it's still one of the best overall RPG Maker games I've played, and one of the few long-running RPG Maker TF games that's actually finished its main story which is a feat worth congratulating.