providing a link to the project is better than any forum or even reddit

For the context, the post in question did not have any link. Links to games look always suspicious. I wonder why there was no link, if the sole purpose was a honest recommendation. My explanation for this is, it wasn’t honest (as you describe it), so their posts do not get flagged for spamming. Post explained in the middle somewhere the name of the game and on what platform to find.

On a different platform, Imgur, I have seen a different approach. They collect popular (old and new) memes and put them in a collection out. These are almost guaranteed to get upvotes and make it to the frontpage. Then with the popularity they edit link to the game page (or other links where they sell something). It’s frustrating.

According to the SEO audits of my personal blog, the majority of my backlinks are from Lemmy instances.

There is probably a bias here, because you are a Lemmy user too. So people might have a personal interest into checking your blog.

As to deal with self-promotion, maybe have them a weekly thread dedicated to it? Because I’m getting nervous about the many advertisement posts made. But on the other hand, I personally like games too and want to recommend others. Which could be seen or misunderstood as advertisement, which in turn applies to other users too off course.