So, I admittedly only got an interest in this because of that video.
Saw somebody link it somewhere completely unrelated as a "Look, somebody reviewed a hentai game!" and gave it a quick skim out of morbid curiosity. Caught side of the spider girl, went "Oh?" and decided that perhaps, it was a worth looking into more closely after all. I'd heard of the game before, but had passed it up when the screenshots didn't really give me the impression that the game was interesting.
...And suffice it to say, I'm actually rather happy that video happened. The game is sneakily addictive once you get beyond the initial 'capture stock, commence fuckery' gameplay loop at the very start. Initial examples that I had seen of it never really brought up the whole "Spirit form" thing, nor did they bring up how interesting the actual breeding part of the experience can get once you actually try to cultivate certain looks.
Trying to pass on my look (Stark white to the point of looking basically vampiric, plus neon blue hair) to new stock has been quite the little adventure, and I still have a lot left in terms of actually picking up new races. I pretty much got up to the titans, and then took a bit of a breeding bender where I really wanted to try and breed up the equivalent of one of my customized spirit forms, essentially. Trying to get that to function has been...a trial, to say the least.
Mostly because I, being the idiot that I am, went "Huh, I guess I ought to try and raise up a nice big wolfy stud for the purpose of getting a high level breeder", not realizing that this essentially meant that I was increasing my chances of turning whatever he fucked into more furries. Either that, or the RNG in the system is also playing their own hentai game where they just enjoy fucking an hours worth of effort...which I think they are doing regardless of the stud, but that's to be expected really.
Once I switched over to a Futa stud, it all started making things far easier. Now it's just a matter of making Platformer sprite maps out of the family tree as I attempt to pass on my skin color, hair color, and try and get at least a few of the more interesting traits in the process. Notable examples being:
-A Vulwarg that I managed to get down to the same size as myself, that somehow has me listed as both mother and father. I'm not entirely sure of the logistics behind that one, other than perhaps using my Futa nature like a bag handle?
-A Ryu that I named Alexandria who was essentially packing a Railgun, and has thus far had a very good success rate on breeding giants.
-One particularly odd Foxen who came from an incest coupling that looked like somebody tried to make a hyper-realistic Carmelita fox. She was sterile, so I ended up selling her off to the angels.
I was disappointed to find out that the Arachne in question was, in fact, a one off and not something you could play as/breed (I get that the logistics of the body are likely a factor in that, but it saddened me all the same.) but the game managed to keep my attention otherwise, especially with all the dragon breeding I've been attempting. One thing that sets this game apart from Hentai Skyrim was a combination of the fact that things fuck each other in the wild very easily (I keep trying to make that happen in hentairim, but its...clunky, to say the least.) and that the breeding system is something I'd love to see in more games of this nature to be honest. Going beyond the frustrating nature of the things not passing down traits when I want them to, I just love trying to get them to look a specific way, as well as trying to breed specific sizes. I got a titan all the way down to my size through constant pairoffs and its bloody hilarious.
The game isn't perfect by any means, but it has managed to hold my attention for quite the chunk of time. Pity that from reading this thread, development seems to be incredibly slow/nonexistent, but maybe one day we'll see a completed product.
Here's to hoping, at the very least.