Sorted roughly by my opinion on how similar each work is to Primal Hunter.

• Defiance of the Fall (review, amazon, goodreads, royal_road): System apocalypse LitRPG. A multiverse spanning series with great hooks, even if there's some deus ex machina and some editing issues.
• The Legend of Randidly Ghosthound (review, amazon, goodreads, royal_road): System apocalypse LitRPG. The System takes over Earth, and Randidly becomes a Heretic. The plot goes off the rails, but you might like that.
• He Who Fights With Monsters (review, amazon, goodreads, royal_road): Portal LitRPG. The story has plenty of humour and a protagonist that drags his moral soapbox in chains behind him.
• Azarinth Healer (review, amazon, royal_road, goodreads): A lone-MC isekai with non-stop action, overpowered MC, and a massive backlog.
• Portal to Nova Roma (review, amazon, goodreads): Portal fantasy with an AI MC who uses his technology knowledge to get ahead in a ravaged, magical world.
• The Path of Ascension (review, amazon, royal_road, goodreads): Scifi cultivation. It's not often we see wuxia in space. It's not common we see it done well, either.
• Jake's Magical Market (review, amazon, goodreads): System apocalypse LitRPG. Initially a card-based LitRPG system, Jake's Magical Market was an engaging read. It's two books stitched together with different focuses in each.

Less similar but you still might enjoy:

• An Outcast In Another World (review, amazon, goodreads, royal_road): Your typical isekai LitRPG novel that only gets better as it goes on through rich characters, good humour, and a great overaching plot.
• Beneath the Dragoneye Moons (review, amazon, royal_road, goodreads): Epic fantasy isekai with a healing-focused female-lead. Some magic school in books eight and nine.