Infernal is a third person shooter without the possibility to switch to first person view. The gameplay is well balanced between swift, hard action and sniping, lurking around corners and walls. Also you'll have to climb, hang, jumps, etc several times to get somewhere. Each weapon you use is one you need to get from an opponent except for really big weapons that you find at certain places. The game is built in such a way that even at the very ending you'll encounter new arms that you hadn't seen before. On top of that you can also do man to man close combat where you'll use your hands and feet. You can even perform combos in such fights!

Ryan can use each weapon in two different ways. Either plain shooting as normal or combined with his supernatural "Infernal" powers which unleashes extra power from the weapon. To do this, Ryan needs mana so you have to make sure you got some left when necessary in tight situations. Also the combos you use in regular fights need this mana. The better your combination moves, the harder they hit your enemy and the more mana they cost.
As Ryan needs souls to survive due to his devilish side you have the possibility to claim souls from the dead. On top of that you can teleport yourself to other places through glass, but not through concrete. These powers go even further: you can also move crates and other characters!

In-game you constantly have an indicator at the bottom of the screen that shows you how dangerous or safe the environment currently is. This can vary between safe, neutral of dangerous and this is very important for your mana and power. Since devilish powers don't like safe environments, your power and mana will be a lot lower in such places than when you're somewhere where it's more dangerous. This results in you having to work completely different depending on where you are.

Despite the quite unnatural main character, the surroundings have been recreated pretty realistic. Everything looks nice and moves as it should. There's for instance a plastic curtain which will stick onto you until you're far enough from it. Then it will fall back due to its own weigth. These physical features have been recreated very realistically and perfectly animated by wind or gunshots. Also the enemy AI is very well done. They react to movement in the whole environment and not only to you. That's also very necessary since you're capable of teleporting objects and persons (including yourself). To make things even more realistic, the makers have gotten some help from a German officer who showed them how to hold weapons, shoot them, reload, ...