Which one should I play first? This or Nier Automata?
I'd go with Replicant first.
Automata takes place literally thousands of years later and some events in it will be more powerful if you know Replicant.
That's one reason.
The second one is that Replicant is still an 11-year old game at heart with touched-up graphics and reworked combat but all of its sticking points are still there. The sidequests are mostly tedious fetch quests that Taro outright trolls the player with, even Weiss constanty ****s on you for accepting them (which is quite funny, TBH). It is somewhat justified by the storyline but still. There's some world building to them, also in the form of banter between Nier and Weiss, so some are worth doing (a few important ones). On top of that, the game does its best to make it seem like a pretty standard affair for some time until it slowly starts to pull the rug from under your feet. Also, the difficulty balance is just bad.
Automata was in many ways the most significant game last gen and it really improved upon the framework laid out by Replicant. It also gets going quicker. Other things like actual storyline, characters and soundtrack (both are among the best ever) is up to debate but gameplay, overall refinement, sidequests etc. I'd all give to Automata. It also pulls off the trademark Nier story structure more gracefully.
Replicant is undoubtedly a special game but it's also weird, convoluted (not like Automata isn't ofc) and can get tedious. It ****** me off sometimes but I really like it at the same time
No instant gratification with this one, I'm afraid but the reward is there.
Replicant-->Automata makes most sense IMO, both in terms of storyline and enjoyment.
