This game has been in development since UE4 launched with their open licensing terms, around early 2015, and it has been one of the biggest adult games on Patreon since they changed their terms to allow adult content in 2016. It's a little different to other titles which are just a bit slow but still make progress or just outright don't have enough support to continue.
You are right however that the crux of the issue is that the game is still in a comparable state to most early prototypes, despite ~8 years of supposed dev time, and it's also still being actively marketed without advising users that it's intended as a F2P with in app purchases. Not sure this is an excellent defence mind you...
As an aside I also wouldn't guarantee this. Helius has been harping on about story mode, campaign, gameplay elements etc. since the game was just called Fallen Doll. We've never seen so much as screenshots and half the descriptions of how it's meant to work don't make sense and/or contradict one another.
I'd honestly be surprised if combat drill is anywhere near complete or if its been a meaningful development focus at any point in this projects history. If and when it does come out it will probably just be some gacha BS he's outsourced to a mobile dev at the last moment which is obviously not what people paid for.
