I figured out how to play it - open this game page on a browser, because it has an imbedded window to run the game without downloading it.
What I did wrong apparently was download the game files and then run them (which didn't work). I first saw your project published while on itch.io desktop app, which does not allow to run the game on the main page itself. Therefore, seeing that it could not be played online, I downloaded it. I tried running the files on chrome, microsoft edge and operagx on a windows 10 laptop.
Hope this helps if anyone else has a similar problem.
Yeah, browser based games are fiddly to make (I think) but are fine for small and short games. The downside later on would be longer loading times as files become bigger (not really in your case - png's and text don't take up much space) and the problem with progress saving.
After finally playing it - I enjoyed it :D
Warmhearted as always. I noticed you used some assets (mostly the music) from your previous visual novels which brought some nostalgia (yes I can be nostalgic over things that happened a couple of years ago lol). Atm marbles are not being used yet, you can take only one job at a time, and there are three different demons.
Marbles could be used for temporary scented candles that could be used to have a higher chance to get different demonic motes or buy items for your demons. Maybe it would be possible to see faces of whoever is speaking on the other side of Commarble. Some instructions about the stats of the creatures would be nice.
Sorry if I went on a bit of a rant, I just can' stop myself when it comes to things that I care about. This demo is already quite well done and I'm sure it will only get better from here. Take care!