As a demo it is really short and is more like a teaser.
It's just an introduction or prologue to the story. There seem to be no player decisions. It's like a kinetic novel with some objects and dialogs to click for additional information.
The art is ok, but the mc's avatar as can be seen in the first 2 preview pics looks rather strange and looking at this avatar for a whole game will be unpleasant.
The art not always follows the text. The only sexual scene is a masturbation image where the mc uses only 2 fingers at the tip of his cock. Probably the story writer meant that the mc's cock is so small that it can only be hold by 2 fingers but the artist failed to visualize this.
As others mentioned, the English is poor.
The story is a mess. Don't expect logic.
The mc's mom has invented kind of teleportation device to travel to a parallel universe. I don't know how they got knowledge of this other "main" universe if nobody could travel there before. The mc also is the first to test the device.
"Travelling" seems to mean that the mc and his alter ego in the other universe "switch" mind and memory, so the mc takes over his alter ego's body. The switch takes place at mc's 18th birthday during a medical examination.
According to dialog this body has the smallest cock of all adults, so the mc becomes officially the only "trap" in that new universe since years. Even his mom has a bigger dick. All people (family, friends, teachers, doctors, etc) know about mc's small/tiny/baby dick and want to help him become a trap. This is a lot of focus on dick size.
The mc has problems to adapt to this alternative society and the alternative versions of his friends, teachers and family members. At school the best friend Vicki/Trish offers : "... you can, as always, contact me for any questions." and then reveals that she is a futanari which the mc should actually know if they are best friends. The dialog doesn't make much sense unless the mc would reveal his origin from another world or would fake complete amnesia before.
This game needs a "small cock protagonist" tag.
A trap in sexual context is a person who dresses like the opposite sex (crossdressing) and hides its own sex, which may fool other people. If everybody knows, nobody is fooled and it is no trap. The dev probably does not know the meaning of "trap".
It is not revealed in the demo what "becoming a trap" really includes. The game has the "transformation" tag. However forcing a short guy with small dick to dress like a girl in a futanari world where "girls" probably have bigger dicks than the boys does not make much sense.