izigame.me

In the current state, I would only recommend Teenage Mutant Ninja Turtles: Splintered Fate to fans of the intellectual property. There needs to be a lot of improvement before I could recommend it to anyone looking for a good action/rogue-like game in general. There are just much superior games already available such as the rogue-likes Hades, Hades 2, and Dead Cells or the numerous action RPGs that share a top-down camera angle like Titan Quest, Grim Dawn, or Path of Exile. I would even recommend Gauntlet Slayer Edition over this game currently. Even for TMNT games specifically, I would still recommend the Cowabunga Collection or Shredder's Revenge over this game currently.
Positives:

Online and local Multiplayer!
Character portraits look great
Voice Acting is good
Music is pretty good, but is all new music for this game. no tracks from previous TMNT shows, movies, or games are included
Character models all look good for the art style
Writing is good. Dialogue is concise and each character has plenty of personality.
If you wish you can skip and/or mash dialogue.
Currency for permanent upgrades is much more common than in Hades specifically, so less grinding is required to continually acquire permanent improvements.

Negatives:

The sound effects are sub-par. Most attacking sound effects are just a general kind of "whoosh" sound and they all kind of blend together. The different sound effects need to be more audibly distinct from each other. It appears like the game makes the same sound effect when you attack whether you hit an enemy or not, but if you do hit an enemy it will layer an additional sound effect on top of the "whoosh". I would prefer something else like how many classic beat-em ups just have two different sound effects: one if you hit an enemy and one if you miss.
Most effects and UIs are low resolution raster images that are stretched on higher resolutions looking very ugly and pixelated compared to the otherwise clean characters and backgrounds. I was specifically playing on a 2560x1440.
Numerous bugs such as characters moon-walking, UIs not scrolling so your current selection is off screen, effects not rendering, menu text overlapping making it unreadable, double dashes triggering when you input only a single dash, etc.
After you defeat the last enemy in every room a menu instantly appears for you to choose an upgrade, but it is easy to accidentally select the default option because the confirmation button, “A” on XBox controllers, is the same as the dodge which you may have started to press before the menu appeared. They need to rework some controls.
The hitboxes do not match the visuals at all.
Your player character will “suck to target” when you attack which I do not like because you have less precise control. For example you may want to attack between two enemies so you can hit both of them at once, but “suck to target” will choose one of those enemies and direct your attack straight towards that enemy. There should to be a setting to turn off "suck to target" if the player wants to.
Some annoying design choices. For example, Donatello's basic attack combo pushes enemies back so the last hit of the combo can often miss unless you move forward before the final hit. This was probably intentional, but I personally found it really annoying.
The game can get really hard to interpret with tons of large effects going off at the same time cluttering the screen. I have the same complaint about Hades, but this game is even worse. Also there are effects that don't show the direction an attack will be coming from such as the linear waves in the Leatherhead boss fight, which they should.
The majority of the animations look good, but some need improvement. For example some enemies are effectively T-posing after they combo and are giving you an opening to attack them; they should have an idle animation, but for me they are perfectly still. This may be a bug, but in general various animations need some tweaking; I wish it was easier to tell if an enemy is staggered or not. Might be a skill issue, but I was having trouble visually identifying if an enemy was staggered or preparing to attack. So overall some animations need some tweaking.
The load times could be improved. For how simple the game is, there really shouldn't need to be load times at all on PC.

I can't recommend Teenage Mutant Ninja Turtles: Splintered Fate for it's base Steam price of ~$30. If they at least fix the majority of the current bugs, then I would probably flip this Steam review to positive, but it is highly unlikely this game will ever be re-vamped enough to truly compete against genre standards like Hades.