So, I had a chance to get through maybe 1/3 of the main story, and likely only 1/10th (likely less) of the total content. Some impressions:
Graphically, this game is phenomenal. Easily the next Crysis, with a graphical jump and feel akin to that 2007 masterpiece. While graphics are typically not the most important thing in games, when it comes to Pandoran immersion it largely
makes the experience, not just elevates it. For those of you who have not been playing games, it may look slightly worse than the movies, and it is, but as far as what's possible in 'real-time' rendering (i.e. a video game), no other game has reached what this game has as an
overall package. Not Cyberpunk 2077, not Horizon Forbidden West, Not Alan Wake 2. Human face models and maybe some parts of the water are slightly questionable, but nothing big to nitpick here. Outstanding stuff overall, especially the ray-traced lighting, foliage density, and textures. Digital Foundry's unequivocal number 1. The sound is also ray-traced to the point of convincing realism where every sound you hear has a directional source (animals, leaves ruffling, etc.). It looks amazing on the PS5, Xbox X, and S as well, so not only on a high-end PC (though it scales well on weaker ones too).
Gameplay-wise, it is a solid experience. For gamers, it might be too much of a condition-optimizing, flower-picking walking simulator, while for non-gamer Avatar enthusiasts, it may have too much combat. I think this middle ground is probably the perfect balance of both, achieving the maximum amount of slow-paced cultural immersion, and the Pandoran hunter-gatherer experience that it could have while still having the budget of a AAA game. To have such a budget, it would have to appeal to the masses to some degree (meaning combat), and the budget from the mass appeal (likely $100-200 Million or more) is what is required for such a graphically impressive game to be available for only $70-100. Luckily combat and some gameplay elements of Far Cry and Crysis fit a lot of the themes of Avatar quite well (the last third of both movies). Voice acting is quite good, but can sound a bit juvenile at times, though, that's likely intentional for a Teen-rated game, and also how it would likely be if Pandora was real (many teen Na'vi around

). Flying feels and looks fantastic as well, but believe it or not, the foliage-boosted ground traversal system is even better. Frontiers of Pandora is a convincing solution to the longing we feel for Pandora, as well as a mirror to our Eywa, Gaia, Earth, which needs to be cared for.
Having said that, the combat can take some getting used to. And in many cases, can be avoided with some stealth and 'run and disable the switch' techniques, followed by running and hiding in the jungle for a bit. Make sure to be at least the minimum level required for the quest, ideally 1 or 2 over. Give yourself points towards health, ideally Vitality IV, and all the other vitalities. Other skills are more or less depending on your style... more damage? Or better food buffs, etc. Either pick top-quality plants and hunting components to build the best bows/armor you can so far, and/or do side quests and such to gain enough clan favor to obtain good bows and armor/clothing from the Na'vi at hometree. Touch all the bellsprigs and tarsyu saplings you can find. Study the biomes and your hunter guide.
@Wind12, which system were you playing on, by the way? Perhaps I can offer more system-specific tips to help! Everyone in this forum deserves to experience this game, as in many ways, it's like a more immersive 100+ hour variant of the movies. I do hope you can get another copy! Btw, the co-op works great, I play on PC while my wife on the PS5 sometimes. Give it a few more tries, and if nothing can help, I'd love to hop on co-op and help you out!