The author did not open reply at cien...so unable to report bugs......
There is a way to report the bugs, but the stupid dev made it unnecessarily difficult than it needs to be:
First. The developer has two Dlsite accounts. Dunno why he thought that this is a good idea, don't ask me.
Second. He forgot to directly link his Ci-en account page to his second Dlsite account. Since the username he listed on Dlsite and Ci-en is different, it made it much harder to discover than it already is.
Third. He limits the bug reporting method only through Japan's local anonymous questionnaire site (marshmallow), in which he gave the link in a random unpinned post. Way to make it harder for everyone (himself included).
Edit 1:
You know what? Maybe they're not the same developer at all. The developer of this game might've made this game using public assets, hence the the identical artstyle (which threw me off the loop). And just like you've said, the developer didn't make a Ci-en account nor provide any proper way to report bugs. The only option is for someone who has the game (the OP), to lodge a complaint through DLsite's review function and tell the braindead dev to provide a way to report bugs.
I'm convinced that the dev is new at game development and is ignorant in marketing at best. Or a certified clueless idiot at worst.
Edit 2:
It turns out, I didn't make a mistake, the info I dug is actually accurate. He made reporting bugs as difficult as humanly possible. And when someone finally found it, he proceed to NOT check his inbox to see any bug reports. Like, what's the point of his ci-en account then?
The dev is indeed a motherfucking moron at best, or an irresponsible piece of shit at worst. It takes a direct callout from the Dlsite review section, for him to move his lazy ass and actually fix the bugs in his game. I really want to punch this idiot in the face.