Outstar got back to me (right away!) on Discord and said, because it's a text-based game, I can include the Dark Pack logo image on the game page. I feel bad about it, so I'm going to embed the HTML into the web page, rather than make the game downloadable. Then, I can include the image in the sidebar which will frame the game the entire time. Since the game will only be playable through that viewport, it should suffice since, in this case, the sidebar is more or less part of the game. And, if the issue is immediacy or viewability, it will be more persistent than one early plug.
Normally, you'd be right re: Choicescript, except that I altered the code to include a persistent save state (hard save, not soft) so that the game can be picked up again in later sessions. Or so people can try different story branches for achieves or deep regret. I can try to zip in the logo and text if, after they see it, the sidebar isn't enough. I'll post early so they can let me know. Cheers! Thanks for the thoughtful response.