This one is a bit unfortunate. Aikagura was amazing IMO. It was actually a fun game and it was fun exploring and finding new zones to see what new enemies there were. It is also one of the few games with breast expansion that isn't temporary or a game over which is rare and awesome. I was hoping for more of the same and with more robust bad effects, especially the breast expansion one being something you could encounter earlier and do a playthrough managing and perhaps having it be a part of multiple enemies (unlikely I know but a guy can dream). At least, even if it was just another Aikagura with some new enemies, animations, and map then I would have been happy.
Instead it feels like this is a major step backwards. I don't really care about the 3D implementation. It isn't a draw to me or detractor. However, the mission-based approach with self-contained levels is a big bummer since it cuts down on exploration and the possibility of carrying over any bad effects to the rest of the game. The animations and enemies seem fine, but the game design just feels way more rudimentary. Hopefully somehow this is just for the demo and it will be a proper metriodvania on full release, but I doubt it. I'll still enjoy it in this form but not nearly as much as I expected after this long of a wait.
Sadly I agree with everyone saying the Sinistar games are superior quality and design. Unfortunately I personally don't really enjoy its vore/death focus and hard game overs (besides the BE ones which are amazingly executed but still either temporary if you escape or a game over).