I had only a very brief look at it.
There are almost no decisions, so currently it is closer to a kinetic novel than a game or a traditional VN with different paths.
The mc starts with a tiny penis. Why? This limits the VN to an SPH audience ...
Why can't the mc just tell his wife about his female underwear fetish?
At some point the player can choose a feminine name for roleplay with the neighbour. This name is then used for the mc even by his wife which is not supposed to know that mc is "crossdressing" and "roleplaying" ...
It is ok to include the female neighbour, but then again : crossdressing as female and joining the neighbour in a hotel room to watch her fuck another man is a very strange course of the story and points towards NTR, voyeur and finally gay content.
In general "sissification" is a form of forced feminization. If the mc has a female underwear or crossdressing fetish, it is voluntary and not forced and so it is not "sissification". The same for transition from male to female : a voluntary transition is not "sissification".
Sex and gender and fetishes and sexual orientation are also independent themes. A crossdressing fetish does not necessarily imply that the mc is gay (/ bisexual) or a transsexual person. According to the dev notes however this is the (kinetic) story of such a transformation :
" the protagonist's journey takes a thrilling turn as they embrace their true self and transition into a trans woman. "
Probably the mc then is also railroaded to gay content?
Main features of "crossdressing" and transformation games are usually sandbox/simulation and an appealing paperdoll model so that the player can decide what pieces of clothing to buy and wear in which combination and in which situation and see it. This is easier implemented with the standard method of using either just a simple grid of slots for pictures of clothing pieces (eg
https://f95zone.to/threads/perverted-education-v1-3301-april-ryan.1854/ ) or by using a drawn paper doll system like the famous public paper doll system by Akabur (Witch Trainer) (eg
https://f95zone.to/threads/the-making-of-a-slut-v1-0-6-austinhaney6969.17961/ )
Rendering all the different combinations of different pieces of clothing and body transformations is usually impossible due to astronomical number of combinations (unless you make a 3D-game which can render the mc in real time).
Removing the freedom to individually dress the mc pretty much removes much of the fun from any "crossdressing" game ...
If you just want to watch pictures/videos of a crossdressing man having sex, you are probably better off just looking for real porn
If you want to just read a novel about a crossdressing man, there are lots of "shared" ebooks online ...