Ok? Games not having cheats is common, if you want to check the CG in games, just use saves shared by people.
Hentai games usually have cheats though. Not all games but a lot of games that require things like fighting farming and stuff.
But it doesn't need them, so, as MR-2 said, just use a shared save. Or play through the game. The game developer doesn't need to add cheats because some people want to skip through it.
