First, I just want to say to the devs, I'm very thankful you decided to let the fans get involved with the development of the game, and for being so active and vocal with us - it's very rare to see this!
To introduce myself, I'm a popular modder for Total War: Warhammer, with one of the largest, most detailed, mods in the workshop with many hundreds of hours of passion and work poured into it. The popularity of my mod, has come from enhancing the flavor and balance of combat, to make it feel closer to lore, and more interesting. So with the same perspective and attention to detail I have for that game, I'd like to give to this game as well, as I know this will be one of the few I truly am passionate about. http://steamcommunity.com/sharedfiles/filedetails/?id=704361604
I feel somewhat hesitant, at this point, to give any feedback, as I know this build of the game is just so early, and you have so much more to add and finish. So what I will give feedback about, will concern the direction of the gameplay, the "feel" of the enemies, and itemization.
Aesthetics of combat and enemies:
1. I know many others are saying this, so I'll add weight to this opinion; increase the speed and pace of combat, to make it feel more exciting, and action packed. Right now, it just feels too slow, and some of the animations for enemies feels boring and uninteresting to look at. For example: Many melee enemies move too slowly, and their animations look awkward , as they don't run or sprint at you, but instead look to be briskly jogging towards you, with their weapons carried in a limp posture. Making cultists, daemons, heretics etc look more wild and dangerous, with their weapons and claws flailing in the air as they charge and scream at you, would go a long way.
If need be, make the maps feel larger, with more room to maneuver to compensate for faster movements, and to also allow room for more cover and destructible objects.
2. Add and improve the sound and visual FX of swinging melee weapons, and make the trails behind weapon swings feel more smooth and fluid. As well as adding more impact to the weapons, making them feel like they are connecting with their object. Ranged weapon fx look and feel so much better than melee at the moment, and they really are awesome. Sound for some weapons need improvement (Bolters need improved sound - a deeper thud upon discharge).
3. Elite enemies, such as Chaos Marines, Chaos Dreadnoughts etc, need to feel much more dangerous, by making their melee and ranged attacks more devastating, impactful, and difficult to deal with. I think you're headed in the right direction with Chaos Space Marines, as they feel rare to come across, and intimidating to look at; but they still feel much too slow and weak, opposed to the unnaturally powerful, fast, and durable enemies they are.
I fully understand gameplay needs to take precedent, but making enemies closer to lore will only make the game feel and look so much more interesting, and legions of 40k fans will love you and this game for it.
Enhancing the Tactical Aspects of Combat and Gameplay:
1. Make cover more common and important; allow destroyed objects and enemies to provide new cover (i.e. Chaos Marines and Dreadnoughts are so large, that when they die, they could provide new cover for both you, or your enemies; or blowing apart a pillar, leaves rubble to be used as cover to advance behind).
2. Make enemies more dangerous and varied in their threat to you; and make target selection, and how you deal with each enemy a challenging tactical choice in how you deal with them.
3. To borrow from the Diablo series, add special versions of enemies - Rare, Unique, Elite, Champion monster packs - which can be randomly seen in missions, with different strengths and stats that can be added for each type of creature and enemy in the game. Although, unlike Diablo 3, stay away from ridiculous or unloreful affixes; e.g. like lasers spawning from the monster, that spin around. These kind of randomized enemies offer a lot to gameplay within the ARPG genre, as well as making players excited to fight and defeat them as they usually are associated with a good chance at loot drops or rewards.
The Loot Hunt:
Now this ties in with the last point I just made, but a greater emphasis on the "loot hunt" aspect of the game, needs enhancing, as this is what makes this genre of game so addictive (alongside fun and interesting gameplay).I realize this game has a different style of loot hunt than other popular ARPG's; but in order for this game to be loved and played for years to come, we need more ways to earn reward during the gameplay.
1. More loot drops (appropriate for your loot system) from enemies.
2. Now this is very important, but meaningful unique, legendary, and legendary set items that drastically alter the builds and gameplay for your characters should be an important addition to this game. To make a comparison again to the giant in this genre, the Diablo series; I feel it is best to stay away from predefined and restrictive sets (like Diablo 3 has), and focus more on open ended items that offer more diverse bonuses, allowing for more flexible builds (like the Legacy of Nightmares jewelry set http://diablo.wikia.com/wiki/Legacy_of_Nightmares).
3. Items that offer new fx, change and enhance skills, and items that add something new that cannot be seen or experienced without this specific item, i.e. an item that allows you to gain a unique bodyguard(s), such as Inquisitorial Stormtroopers; or a special kind of skull probe that enhances your ranged skills etc. There's a lot of material from the lore, concerning the Inquisition, which can be used and drawn from.
4. Rare, Unique, Elite, and Champion enemy packs, to defeat and to make players feel excited to hunt, and be rewarded by the Inquisition for slaying.
So I hope my initial feedback might help in the direction of the game, as I truly want this game to be the best it possibly can!