EDIT: Upon the discovery that this game has player 1 advantage, manifesting in the form Player 1 being able to perform combos that Player 2 cannot, I've dropped my score from 3 to 2/5. This is an unacceptable oversight in 2023 and prevents this game from being taken remotely seriously as a fighter.
Mortal Kombat is the first video game franchise I ever truly fell in love with, so it pains me to say this, but this game is heavily, heavily flawed, lacks in basic QoL features we've come to expect from both the MK franchise and the fighting game genre, and frankly feels unfinished.
The single player content is mostly quite bad. The seasonal invasion fights are not remotely fun at all. Customization has been severely gimped since 11, most characters only have 2 skins and then a bunch of colours. There is all sorts of random features lacking like the ability to pin moves on the screen during training mode and the ability to change your characters costume on the character select screen, something so simple that requires the opening of an entirely separate menu. The online also has a lot of problems, you can't make your own rooms, loading screens taking forever, inability to filter out wifi warriors and more lag then you'd expect from MK. Everything about the game in terms of content feels rushed.
For more subjective stances, the character design ranges from excellent to godawful, with Tanya easily being the most butchered, and most others falling into the "bland" category. Megan Fox voice acts a character people have been asking to return for 15 years and gives the worst, most uninterested sounding performance I've heard in a triple AAA game, destroying the immersion every time she's on screen. The story mode is... better than MK11, but still has a lot of problems. Scorpion and Sub-Zero conflict is very lukewarm, probably the biggest letdown for me, the villains are as usual portrayed as pathetic jokes and I'm convinced whoever came up with the ending was likely on crack. What disappoints me most however was that despite this being a fresh start for the franchise with the new era and all, the game devolves into a direct sequel to the plot of MK11 and leans extremely heavily into the multiverse and timeline convergence garbage. The gothic, dark atmosphere of older MKs is largely absent, as it has been for a while now I'm afraid, and what we get in its place feels more akin to marvel with gore than Mortal Kombat. Everything about this games story, character designs and presentation feels stale, safe and corporate, a far cry from classic MK which did not concern itself with catering to mainstream expectations.
The reason I don't score the game lower is because the combat system and gameplay is mostly very good, and a massive step up from MK11. However I would not recommend this game to anyone who is not interested in exploring aspect to its full potential (playing online against other people), the single player experience is absolutely not worth it. It hurts to say but I do not feel this product nor its developers are respectful of their audience.