Warhammer 40,000: Inquisitor - Martyr is an action-RPG that combines the grim darkness of the Warhammer 40k universe with the open-ended nature of the Diablo series. As you might expect from such a mixture, Inquisitor - Martyr is all about exploring vast and randomly created levels, collecting more loot than any one person could possibly carry, messing around with a variety of weapons and abilities, and naturally, mowing down Chaos forces by the hundreds.
Inquisitor - Martyr is still in Early Access, though progress seems to be going at a steady pace as the developers have just released a major update. The unassumingly named Patch 0.7.0 has brought with it a brand new class in the form of the Psyker (think of them like mages), the very first chapter of the single player campaign along with a better tutorial, a new terrain setting to explore, and naturally, a whole bunch of gameplay improvements and bug fixes. If you're interested in all of the details you'll find the full patch notes over at the Steam announcement.
Besides all of the new content to play around with it, patch 0.7.0 has also brought with it a brand new campaign intro cinematic. It's not exactly action-packed which is a bit of a disappointment, but it should at least get you in the proper Warhammer 40k mood before everything goes ballistic. Have a look, it's not very long:
The final thing worth discussing is whether Inquisitor - Martyr is something you should pick up while it's still in Early Access. You can find my detailed answer in a review I did a little while back, but if you prefer something shorter I'll leave you with this conclusion:
"Warhammer 40k: Inquisitor - Maryr is currently in early alpha, and despite most of the gameplay elements already being fun to toy around with its by no means polished, balanced, or feature-complete. So if you're looking to grab a brand new ARPG that you can sink hundreds of hours into, I'm afraid Inquisitor - Martyr is just not there yet.
On the other hand, if you're only going to play it for a couple of hours every now and then until it finally releases, then you can consider grabbing it as I really do believe Inquisitor - Martyr has a bright future ahead of it. That said, I would still suggest you wait for that future to arrive as the current price is extremely high for an early alpha game."