Obviously it is a classic staple of the Xbox and was extremely successful, but what in particular made it so successful? Halo games always appear to be critical and commercial successes, but growing up it was Combat Evolved that appeared to dominate my childhood and the memories of my parents' generation.
Whew, where do you even start with a question like this? Everyone is going to have their own interpretation of what makes a game good, so instead I want to focus on what Halo did that was different than other FPS and console games at the time. From this perspective, it succeeded largely for three reasons: genre accessibility, story and level design, and multiplayer.
Halo was released in the fall of 2001, but it had been in development for several years before that. It went through a bunch of changes before finally becoming a first-person shooter (FPS). This was a big deal at the time — in the 90s, FPSes were basically only considered viable on PC, with games like Quake and Doom considered state of the art. Releasing an FPS on a console was a big ask.
The problem for a lot of console developers was figuring out how to make controls work on a gamepad. On a PC, you rest your left hand on the keyboard and keep your right hand on the mouse, allowing you to move, aim, and shoot without needing to reposition them. But a gamepad has limited inputs — and in the 90s, most only had a single D-pad.
The N64 had what is widely considered the first popular console FPS, GoldenEye 007, and while it has a control scheme similar to a modern FPS, it was still fairly clunky to use. The key insight was using the two directional inputs to control movement and orientation independently.
Despite being originally developed for the Mac, Halo become inseparable from the Xbox, marrying the design of the controller to the actions the player can take. The massive controller had three directional inputs: two analogue sticks and a D-pad. It also had two triggers on the back of the controller, and a series of face buttons.
I realize that this is so common now it seems silly to describe, but it's tough to overstate how revolutionary the design was. The N64, with its weird trident shape had just one trigger and one stick, and its design meant that it was impossible to use all the buttons on the controller without moving your hand around it. You could use the analogue stick and pull the trigger or you could use the face buttons, but you couldn't do both at the same time. What the Xbox controller did was give players the ability to use both sticks and triggers at the same time — and still allow the user to use one stick and face buttons.
Bungie took this design and ran with it, creating a control scheme that was so brilliant that in retrospect it seems obvious. Left stick to move, right stick to aim, trigger to shoot. These are the primary verbs of the FPS, and for the first time on a console, players could do them without needing to move their hands — just like on a PC.
Everything in Halo was designed around the dual-stick input. Analog sticks controlled by a thumb are much less precise and harder to control than a hand on a mouse, so Bungie developed a system that would make targets feel stickier, drawing the crosshairs to them. Today we call it aim assist.
PC shooters are all about speed and agility, with games like Tribes requiring hyperfast reflexes and manipulating the physics engine to achieve incredible speeds. But an analog stick isn't as fast as a mouse, so Halo slows down the combat considerably, relying more on cover than on reflexive aiming. It also introduces a recharging health bar, so that when players inevitably get hit they don't have to run around a level looking for limited health packs.
Another brilliant change made for consoles was reducing the number of weapons the player could carry. The original Doom has eight possible weapons and you can carry all of them at the same time. On a PC, switching between weapons is as easy as pressing a number key, but a controller has far fewer inputs. While Bungie didn't significantly reduce the number of guns in the game — in fact, they significantly expanded them — they limited the number the player could carry at a single time to just two, with a single face button to swap between them.
Now players don't have to spend their time doing inventory management; they just swap from one to the other and back whenever they need to. This also creates a new layer of strategy, forcing the player to work with what they have instead of what they want. Running out of ammo on a gun makes it useless, so you better find something to replace it before you get killed.
Because of these design decisions, Halo differentiated itself from PC games by being less about rapid movement and more about tactics. Weapons have different strengths and weaknesses that force you to use them in different ways, enemies dodge in and out of cover, levels are built like arenas connected with corridors that allow the player to slowly push through.
All told, these design decisions made Halo a very accessible console FPS for the first time. But while its game design is brilliant, that's only part of what made it a success.
It is impossible to overstate how mindblowing Halo looked. I'm not talking about the graphics — they were about average for the time — but its levels. Until this time, FPS levels were generic industrial-cum-space station. Think lots of repeating diamond plate, caution stripes, portholes looking out into space. They gave you a location to run around and shoot things, but they were missing a sense of place.
Halo was announced at Macworld 1999. Yeah, the iconic Xbox game was actually going to be a Mac exclusive during its development. It was near the end of the presentation that Steve Jobs started talking about games coming back to the Mac and played a trailer for a very early version of Halo. It started inside, but about halfway through Master Chief did something that few shooters had done before: he went outside.
The reaction was overwhelmingly positive. In the presentation hall, people were on their feet applauding. One reporter described it as "divinely inspired" People could not wait to play this game.
What Halo did so well is create a world. You weren't just in some blood-soaked future arena, you were on a UNSC cruiser. You weren't just in a space plane, you were on a Pelican. Those weren't just aliens, they're Covenant, and they looked like nothing we'd ever seen in a video game before. Every level in Halo looks like a real place, not just a level.
And where they did that best of all was in scale. You might be Master Chief, an unstoppable genetically engineered superhuman hellbent on saving the human race from extinction by obliterating every alien in your path — but once you set foot on the Halo itself you suddenly feel tiny. You're surrounded by towering alien structures, running along catwalks above bottomless pits, dealing with huge vehicles like tanks and aircraft. It felt huge in a way that other FPS games never did.
A key reason for this was that lots of Halo takes place outside. Just by taking the roof off their levels, laying down grass, and filling it with plants, players suddenly had the world open up around them. You weren't just navigating an endless maze of metal rooms, you were moving between buildings, pushing forwards towards your goal across the surface of a place. The game felt huge in a way that no other game had before.
Despite its slow pace of gameplay, the story is fast. You're on the clock right away as your ship gets boarded, and it doesn't slow down from there. Humanity is on their back foot, slowly being crushed by the overwhelming force of the Covenant. Even if the story isn't particularly original, it's told well. It feels like you're a superhero in a movie, rescuing marines and mowing down enemies all in the glorious name of saving the human race. You better get me into that control room, Cortana, or the Covenant's going to win.
Halo arguably created the modern video game story form. In Doom, you're a space marine and there are enemies to kill. In GoldenEye, you're James Bond in the movie GoldenEye. But in Halo, there are stakes. There's emotional motivation behind what you do. You're not just killing an enemy because they're standing between you and the blue keycard you need to get to the next level, you're doing it for all the marines you couldn't protect on the Pillar of Autumn.
The biggest shortcoming of the game is its length. Due to the late scramble as Bungie shifted from Mac to Xbox development, the story was short and barely finished. But Halo has one more key feature that solved that in a way that set it apart from just about every FPS at the time.