Doom 2016 - what makes it so good?

The basic gameplay of Doom 2016 consists of 2 modes, which are alternated:

Combat

Unchanged from the original Doom and Quake games. Essentially it's a game of moving in a direction to avoid enemies while shooting in another direction while collecting powerups, like Robotron. The fact that is 3d rather than 2d does add the necessity of aiming up and down (although this wasn't even present in original Doom, which was just a 3d rendering of a 2d game). More recent FPS games feature hiding behind cover and automatic regeneration of health as essential elements of combat. The absence of these marks this as a throw back to the original Doom. (There is scenery which blocks line of sight and makes the combat more tactical, but hiding is not viable.)

However there is one new addition: the 'glory kill' system.

Exploration

Combat is broken up by sections of exploration. These are made interesting by:

Personally I find exploration less fun than combat. But the above items do bring it up closer, and it also fulfils a role of something to do which is a break from intense action.

The sugar that makes this is an AAA title:

There are also a number of other systems layered on top:

Collectable weapons

As in the original Doom, you collect more powerful weapons the further you advance in the game. This makes the player feel more powerful. The more powerful weapons have limited ammo, meaning they cannot be used all the time, so they also introduce new tactical decisions of which weapon to use which makes the combat mode more varied and interesting.

Variety of enemies

Each type of enemy behaves in a different yet predictable way. On encountering a new enemy type the player is forced to discover the necessary tactics to counter it. Then the player is attacked by multiple types simultaneously, requiring rapid thinking and deployment of the already learnt tactics, in more and more challenging combinations.

Weapon modifications

Most weapons have 2 modifications available. They are unlocked through exploration pretty easily, and the player is given the management decision of which modification to unlock each time. This gives the weapon 2 alternate firing modes, for a total choice of 3 different kinds of fire from each weapon.

Weapon modification upgrades

Each modification can be upgraded 4 times, providing unique bonuses when that modification is used. Modifications are purchased via points, so the player has to decide what is best to buy. The points are awarded for exploring secret areas, killing enemies (which is pretty much essential anyway, so these points are regular and automatic) and completing challenges (see below).

Player character stats upgrades

Each level contains one or two stat upgrade points. Usually they are pretty easy to find, so progression is mostly automatic, but the player is given the tactical choice whether to upgrade health, armor or ammo capacity.

'Rune' specials

Each level contains 2 runes, of which 1 is easy to find. After finding the runes a special challenge must be completed before they can be used. These special challenges take the form of combat in a special arena with special limits imposed, e.g. limited health, time, weapons, ammo. Once runes are found and unlocked the player must then choose which runes to equip - they each provide some bonus only while equipped. The player is limited in the number of runes he can equip at once, so he is forced to choose carefully, optimizing the combination of runes that work best together and perhaps changing the equipped runes depending on the situation and what challenges he is currently aiming to achieve. Examples… TBC

Challenges

Each level has 3 unique challenges which give weapon modification upgrade points. Each weapon modification has one challenge to unlock the final upgrade. Each rune has one challenge to upgrade it. So at any one time in addition to winning the combat the player is trying to remember up to 3 or 4 current challenges to complete during the combat. Examples… TBC