This game fits multiple genres.
TPS, PVE, CO-OP, class-based, horde shooter, looter shooter.
These genres do a very good job of summerizing what you should expect from this game.

I'll list a few of my favorite pros, as well as what I think are the most relevant flaws.

Pros:
-1: Not predatory.
You can get nearly every item in the game without spending premium currency.
You don't even need to pay for premium currency, you can get it from trading with other players.
-2: Full Cross-play and Cross-save.
This game is a leading example of full cross-play and cross-save, along with that one popular battle-royale.
-3: Optimized.
Despite having high-end graphics, this game is able to run on Android and handhelds.
Fresh air compared to other games getting released these days...
-4: Customization.
Custominzing characters is pretty fun, even if it does take a while to unlock good mods and color palettes.

Cons:
-1: Very little challenge.
When you first try the game, you will notice that enemies barely tickle you.
Even if you're playing on a steering wheel it will take a long time for this to change.
This is mostly because the game is multi-platform and it takes accessibility very seriously.
-2: The enourmous power gap between new and veteran players.
If you dedicate a couple days playing this game you might become a lot more powerful, but you'll notice that you're not even remotely close to an end-game player, and that you'll have more fun playing with people your level.
-3 : Watered down class-based aspect.
There are now 64 classes (warframes) in the game, and yet there are basically zero meaningul synergies (anything other than increasing a number) and every single class is perfectly capable of soloing any type of mission, even if they only excel in one mission type.
-4: Wikislop.
You gotta have the wiki open to see where the stuff you want drops.
-5: Lore.
The game doesn't explain its lore very well, no one understands it and people who say they do are liars.