I think, from my personal view of course, that Warframe (like any other type of new game and sorta new game), lacks of immersion and dynamism. But what I mean?
I mean, that the environments and the npcs overall, are flat. The open maps are lifeless, enemies walks mindlessly at you, same ships tileset, pets are like statues and many more "little" things.
I bet you would like to see your Kavat fish with you and eat the catch, or see him trying to climb a tree, hunt a bug or hear a purr when you pet him. That thing stares at nothing instead, it doesn't even blink!
It would be wonderful to have the chance to toss a ball to your Kubrow and play a game of fetch or see him while he digs a hole to hide something.
For the enemies I would like to see an impression of tactics when they approach, maybe add some formations, more actions like covering or escaping out of sight or more air combat with drones, turrets, shields, cameras to spot where you are or just more military behavior .
Bosses should actually command the operation towards you instead of waiting in their room, you should get to fight their platoons and THEN fight them.
I would like to see npcs in relays, open maps, ecc, interacting a bit with each other and something similar to seasons in areas like the Plains or Orb Vallis. Of course they should go well with the planet, I wouldn't put a green and luscious spring on Venus but I would put a winter on Earth with a little bit of snow and a short trail of footsteps behind you.
Some already visible fishes in the hot spot areas will be good too.
So, this is what I mean with immersion and dynamism, some sort of eye candy that is worth stop playing for.
A sidenote for all us fashionframe heads, I would add a shopping cart in the game. When you are looking for a new stile for your frame, it would be cool to select a syandana that you want to buy and see it STAY THERE when you switch for the shoulder piece that magically doesn't disappear when you are changing helmet. When you are done with the looking, you check the total price and that's it.
Those are only ideas, things that I will se in a interesting way and a lot can be done. I'm quite sure most of us will appreciate that kind of effort.
Sorry for the long post btw, here's a potato. 🥔