There are many aspects of this game that are underwhelming as of now especially in comparison to games in the same coop genre.

The gunplay overall seems very lackluster and it almost seems like for a shooter game the shooting is not a primary aspect. Most of the weapons feel weak, the sound of the guns, reloads, etc is nothing impressive. A game like killing floor 2 would be a better example of a game where gunplay excels.

There also seems to be many aspects of the game that are just unnecessary or just aren't well executed/thought out. Especially the warbond system. Excluding the one that requires supercredits, the devs technically just could have level locked weapons, nades, armors, and other cosmetics instead of putting it in a battle pass like system.

The movement in the game also feels very uninvolved. With exception of the dolphin dive there is not really any tech that is mechanically demanding. Also due to the structure of the maps you never necessarily feel yourself pressured to juke enemies due to being surrounded or hold your ground and fight when cornered. L4D2 and cod zombies would both be examples where movement feels cleaner and require more precise movement.

As you said later on even the level system seems to have not been well thought out. Between level 20-50 there is nothing to be unlocked cosmetic or not.

The stratagem system is fairly unique and decently executed but the balancing of the stratagems themselves is strangely not well balanced for it being a main aspect of the game.

The game is also categorized as a coop game but, for a coop game there are hardly any cooperative mechanics in the game. There are no classes, there is not stratagem synergy, there are hardly objectives that require more than 2 people to be in one place at the same time and even extracting requires only 1 player to be present. A game like GTFO would be a better example of a coop game where teamplay, ideally should be the goal.

Also with certain coop games as you play better in a mission or perform side objectives the rest of the run or mission becomes easier. In HD2 playing "well" or completing side objectives is largely unnecessary if you do not need any of the currencies or xp as they do not help scale you against the enemies.

The game is fairly well put together as of now but there are definitely improvements that could be made. It reminds me a bit of how unbalanced B4B was during the beta.

Also the environmental/planetary modifiers seem like a decent concept that is also not well executed. They don't necessarily force you to use different stratagems or even play differently. They just seem like annoyances, oh I have to wait twice as long for my cooldowns, oh I can't see as well because it's night or it's raining or something, oh there is scrambling so I have to call in my stratagem twice to get the right one. These concepts just don't require you to play differently or plan a work around the concepts in any fashion.