I play this game with my GF, and we deeply enjoyed the first one.
But here, its kind of a different story.
The game is overall "decent". But some/alot of things really drag it down :


- Damage trinity. Why ? In a rogue-like ? Please, no. The game already lack weapon and turret diversity, and on top of that they are all only useful in specific situation. Plus every hero only have access to half the weapon, and the result is : you have 2 turret, and 2 weapon for any situation, litteraly. One melee option, one long range option. You can't do that in a rogue-like, and even less with so few weapons and turret. Let us make choice depending of our preference and synergy, not enemy weakness.

Solution : Remove damage trinity, and eventually improve existing weapons so they feel more "unique", rather than being more or less the same, but different damage type. Thought removing the weakness/resistance system would really be the biggest improvement by far. New turrets wouldn't hurt too.

- Variety : Thats the game biggest issue here, by far. Low character count, with not much gameplay difference. Low weapon count, with not much gameplay difference. Low turret count with not much gameplay difference. Perk (leveling one, or merchant one) being mostly stat buff = almost no gameplay change. No difference between 2 same blue weapon (no weapon affix..). On top of that, the damage trinity...
Result is : every game feels almost exactly the same. Wich is the exact opposite of what a rogue-like should be. The biggest change happening from one run to another is the map skin you choose at start, and that's it.

Solution : Rework characters so they actually feel unique in what they bring to the team. Shroom is kinda great in that aspect, even if her gameplay is about the same, at least she brings heal. What other characters brings ? Not much beside damage, or fast turret repair and turret buff. 
Give us TRULY random weapon loot : Add random affix to them. What's the difference between 2 blue flame-thrower ? Whatever affix they have, simple.
Give us TRULY game changing perk, and that works everywhere : weapons affix, on merchant perk, on hero perk, on meta perk.
For example : 
- The longer i stay in a room, the more i (or turret, or both), deal damage. (encourage static gameplay)
- Right click deal damage to turret instead of healing them, but the buff it gives them is crazy. (encourage risky gameplay, and cooperation for buff/healing) 
- Can't deal damage anymore with weapons, but hitting targets with them charge the skill and ulti WAY faster. (encourage playing mainly around your skill) 
- Disable turret when i stand in the same room, but increase my damage or whatever. (encourage character gameplay) 

- Deal 60% less damage, but gain 10 wits and run 50% faster. (encourage fast rotation and buff/healing turret gameplay) 

That's just some fast-thinking example. Go crazy with them, that's the whole point of a rogue-like, please.
Oh let us carry more than ONE merchant perk.

As a side-note : Dungeon of the Endless already suffered from this issue, but it was kinda ok because the game was more about the strategy and management, and less about the action. Here, with 3 character (or 2 as 2-player), less strategy (removal of the lighting management), more action, and no character death/recruitment, it hurts way way more. Because the gameplay is now mainly about action, but there's no variety there.

- Meta progression : Ouch. On top of NOT being very rewarding, its just a pain in the ass. The quest system should have been only for cosmetics unlock. Here its just boring, and the reward is dull : Perk are still NOT game-changing, again. The same +x% damage, the same +X wits. That's just straight buff, nothing more. Weapon mods feels dull too. So in mid-game, some weapons are better than other because i modded them ? Dude, as said earlier, theres already so few options, don't reduce them even more.

- Solution : Just give us a leveling tree where we get to choose perk with a character currency, and we can't buy all perk so we have to choose. At the end of the tree there's 2 or 3 unique but gameplay-defining passive and we must choose only one, end of the story. That's simple to understand for player, gives enough variety, and that's it. Perk and passive may modify stat, the way the skill and ulti works.. whatever. 
Regarding weapon, just do what Star Renegade did : Let us choose weapons with increased loot rate, and weapon with decreased loot rate. And let us choose wich weapon we start with (at level 1, no affix, no rarity). 

Overall, the issue is that you changed what the game was about (compared to DotE) : Way more actions, way less strategy, and that's absolutely not an issue by itself. But this should have come with what is absolutely necessary for a rogue-like action game : More gameplay variety, more meaningful decisions, more build synergy, more meaningful stuff. Instead, you went the opposite : the game is actually less synergic than DotE, and try to contain and control any potential snowballing. There's less character choice, and less variety in their gameplay. Perk and stat have less impact. Turrets too. Weapon too. Huge, huge mistake, sadly