As is typical for products with this ID format (DLsite standard), the game contains explicit adult content.
Based on the RJ code, this is most likely a work from (a Japanese digital content platform for doujin/games/audio). The code RJ01295900 suggests it is likely an audio drama / voice work (ASMR/シチュエーションボイス) . -ENG- Welcome To Seeding City- -RJ01295900-
Another popular analysis involves the hidden Morse code. At 41:09, during the power outage sequence, a series of high-pitched beeps can be heard. Decoded, it spells out: Y O U A R E T H E A R C H I T E C T . Fans believe this suggests that the "Refugee #4092" (the listener) actually designed the city and wiped their own memory to experience it fresh. As is typical for products with this ID