Modders are already fixing NieR Replicant's PC issues
They've already tackled a couple of the port's most glaring problems
It hasn't taken long for players to discover some frustrating technical issues with NieR Replicant Ver.1.22474487139. Namely, the game doesn't work well with high refresh rate monitors and unlocked frame rates, not to mention a few other irritants too. But fans have released a couple of mods to fix these issues, so you can fully concentrate on hacking, slashing, and getting quite emotional.
One of the most commonly reported issues with NieR Replicant has been how it handles higher frame rates. Those with high refresh rate monitors who play above 60 frames per second have found the game's animations speed up alongside them. Play the game at something like 120 fps and your character will zip about at warpspeed.
Other issues include mouse cursors constantly resurfacing when playing with a controller, and frame rate drops when plugging in, or unplugging your controller.
Thankfully modders have come to the rescue if you've been a victim of NieR Replicant's issues. There's the Special K tool by "Kaldaien" (must, resist, cereal, joke), which gets rid of the mouse cursor issue, lets you set your own frame rate limit, disables the game's V-Sync, and more. Special K was an important tool for fixing NieR Automata's PC version woes too, so it's good to see it make a triumphant return here.
And finally, there's the aptly named NieR Replicant High FPS Fix which lets you run the game at over 60 fps without that weird animation issue.
I've been living and breathing NieR Replicant for review (I am literally about to write it up after this), and I've not encountered the high frame rate issue. I suppose I've got lucky so far? But I have encountered the mouse cursor popping up (not really that big a deal to me), and the weird frame rate drop when plugging and unplugging my controller. Oh, and one crash to desktop early on in my playthrough, but nothing since then. Honestly, it's largely been good to me.
If all this mod business sounds too finicky, you could wait for Square Enix to patch NieR Replicant. Although, who knows how long it'll take, as Square Enix are only now getting around to fixing problems with NieR Automata's Steam release - after four years.