In the late '90s, 3D polygons were ready to take over the gaming industry. A good chunk of the market at the time consisted of 2D Platform Games, so developers had the job of figuring out a way for those obstacle courses to properly transition into a 3D space. The answer was to seemingly downplay the "obstacle course" part.
Enter the Collect-a-Thon (short for "Collection Marathon"), a style of Platform Game that was very popular in that era, inspired by the advent of Super Mario 64, which sought to take advantage of the new axis provided by 3D polygons through large, explorable worlds where players could move around freely. This, however, led to some new problems: traditional Level Goals at the end of linear paths looked a bit pointless in this new open-world reality. 3D perspective also made it harder for players to gauge height and distance during jumping sections, which wasn't helped by the camera now being dynamic instead of fixed (player breaks for camera adjusting were frequent back then). The solution then was to sideline the actual platforming and turn exploration into a major part of the experience, but that also meant having to encourage the player to look around for sort of reward that could also function as a goal in order to do so; that's where the collection aspect comes in.
The core formula is as follows: collect X number of Y things to advance further into the game. There are barriers, natural or not, that will prevent the player from just moving on to the next level unless they explore and collect enough of the resident Plot Coupons; however, very rarely are those conditions unfair (especially in the early game) and having to gather every collectible possible is never necessary in case you just want to beat the Final Boss and finish the game, Golden Ending notwithstanding.
Collect-a-Thons are known to fill their worlds with trinkets of various types, each in their own tiers of importance. Primary collectibles are rare and the most important to get, always requiring one or more objectives of relatively moderate-to-hard difficulty to be completed before awarded (they're often shiny and/or gold, to highlight their importance). Secondary and tertiary collectibles, on the other hand, are plentiful and serve to directly or indirectly help the player obtain primary ones, either by outright granting said primary collectibles after enough of them are picked up, guiding the player towards points of interest or being used as "currency" for new moves and weapons that will be necessary in the long run. There are also "bonus" collectibles that are generally optional to a non-100% Completion run, meaning they can be either easier or harder to collect depending on how useful the reward provided is.
The genre would eventually lose popularity somewhere in the mid-'90s as games like Grand Theft Auto III would expand further on the open-world concept, thus making Collect-a-Thons redundant for the most part. That said, the notion of exploring worlds in order to find and collect things was not lost in many modern games. In fact, it still persists even two decades later. 3D Platformers, however, would fall to the wayside by the late '00s just as 2D ones returned to viability in the market thanks to the success of New Super Mario Bros. and other games of the type that thrived on handhelds and even consoles. The term "Collect-a-Thon" itself is relatively recent (back in the '90s, those were just good old Platform Games, except in 3D) and sorta carries a derisive tone to it, but there are many who still utilize it unironically, especially for more modern takes of the genre. The eighth generation would see a small-scale revival of the collect-a-thon in some indie circles with games like Super Lucky's Tale, A Hat in Time, and Yooka-Laylee, though the difficulty of developing with the Polygonal Graphics required of the genre compared to sprites has limited the number of indie developers attempting to take it further, unlike the large-scale 2D platformer revival in the seventh generation.
Reminder that not every 3D Platformer is a Collect-a-Thon (following the modern, agreed-upon definition). They might borrow some elements that are part of the genre, like the Crash Bandicoot games that require collected crystals to progress, but unless they feature enough explorable areas and gated progression under a specific number of objects, they don't count. Similarly, 2D Collect-a-Thons do exist as well, in which case expect several branching paths and side-areas featuring important collectibles.
Compare Metroidvania, which also encourages exploration and employs gated progression, but is usually not divided in individual stages, instead featuring an interconnected world.
Examples
- 40 Winks
- 102 Dalmatians: Puppies to the Rescue
- Ape Escape
- Astro Boy: Omega Factor: A downplayed 2D example, as the levels are mostly linear, but meeting every character is crucial to upgrading your Omega Factor.
- Balan Wonderworld
- Bang-On Balls: Chronicles
- Banjo Kazooie:
- Banjo-Kazooie
- Banjo-Tooie
- Banjo-Kazooie: Grunty's Revenge
- Banjo-Kazooie: Nuts & Bolts: Downplayed example, as the game focuses more on constructing vehicles than raw platforming. Nevertheless, there is still platforming to be found, the levels are open-ended, there's an huh world, and the game still focuses on collecting Jiggies for progression.
- Bubsy 3D: Downplayed in that levels are Point A to Point B but the collectables are needed to get a different ending.
- Bugs Bunny: Lost in Time
- A Bug's Life
- Castle on the Coast
- Cavern of Dreams
- Conker the Squirrel:
- Conker's Bad Fur Day: Downplayed. There are some open areas at the beginning, but, from 1/3rd of the game onwards, it's more or less entirely linear and filled with scripted sequences.
- Conker: Live & Reloaded
- Twelve Tales: Conker 64
- Corn Kidz 64
- Croc
- Demon Turf
- Donkey Kong 64
- Drawn to Life: The first game is a rare 2D example; the player has to retrieve items in order to complete levels, which are very explorable.
- Duck Dodgers Starring Daffy Duck
- Earthworm Jim 3D
- Ed, Edd n Eddy: The Mis-Edventures
- Epic Mickey
- Fez: A 2.5D example with possibly the bare minimum to qualify. You just collect cubes (some of them divided into eight smaller cubes) and anti-cubes; your combined total of cubes and anti-cubes opens certain doors for progress, and determines which ending you get.
- Frogger The Great Quest
- Gex (especially Enter The Gecko and Deep Cover Gecko)
- Hargrave: You need to collect enough energy cells to unlock access to bosses and their weapons, as well as the final section of the game.
- A Hat in Time
- Haven: Call of the King (more of an Action-Adventure, but platforming is still highly featured)
- Hell Pie
- Here Comes Niko!
- Jak and Daxter: The Precursor Legacy: Sequels would abandon the genre altogether in favor of a Grand Theft Auto-like Wide-Open Sandbox structure.
- The Legend of el Lobodestroyo Vs. la Liga de los Villanos
- Muppet Monster Adventure
- Ninjabread Man
- Poi
- Psychonauts: Zigzagged. The game has loads of collectibles, but progress is mostly independent of them. We say "mostly" because there are many instances with obstacles requiring abilities only obtainable under a specific rank. Collecting figments and challenge markers is necessary in order to rank up in the first place.
- Psychonauts 2 is a more downplayed example. Like the first game, Psychonauts 2 is a free-roaming, story-heavy game where you collect various collectables that you use to level-up and gain new powers that help you navigate the worlds. While 2 doesn't block story-progression without this-or-that ability or item, there are various collectables — including vaults — that you can't get without abilities gotten with a high enough level.
- Rayman 2: The Great Escape: Downplayed. Most levels are linear and you only need to get to the end to complete them, but you do need to collect a certain amount of Yellow Lums to progress in the game, and the PS2 version does have hubs that are explorable to an extent)
- Rocket: Robot on Wheels
- Shadow Man
- Sly Cooper and the Thievius Raccoonus: Downplayed. Most levels are linear, but the hubs are explorable to an extent, similar to Spyro The Dragon. Sequels would feature open environments, but abandon the mandatory collecting.
- Sonic Frontiers
- SpongeBob SquarePants:
- SpongeBob SquarePants: Revenge of the Flying Dutchman
- SpongeBob SquarePants: Battle for Bikini Bottom (console version only)
- The SpongeBob Movie Game (console version only)
- Spyro the Dragon:
- Spyro the Dragon (1998)
- Spyro 2: Ripto's Rage!
- Spyro: Year of the Dragon
- Spyro: Season of Ice: This and the other GBA Spyro games are rare sprite-based examples, relying on Isometric Projection.
- Spyro 2: Season of Flame
- Spyro: Enter the Dragonfly
- Spyro: Attack of the Rhynocs
- Spyro: A Hero's Tail
- Spyro Reignited Trilogy
- Super Lucky's Tale
- Super Mario Bros.:
- Super Mario 64 (Trope Maker and Codifier)
- Super Mario Sunshine
- Super Mario Galaxy: Downplayed. This and its sequel are officially considered "course-based" instead of "open level-based" by Nintendo, but there are a few explorable areas in both games.
- Super Mario Galaxy 2
- Super Mario Odyssey
- Bowser's Fury
- Tak and the Power of Juju
- Tinykin
- Togges
- Tonic Trouble
- Toy Story 2
- Ty the Tasmanian Tiger: The first game is a straight forward collect-a-thon. The second and third games take on a more mission-based open world playstyle, but collecting is not mandatory. The fourth game ends up being a linear 2D platformer.
- Vexx
- Wario World: Zigzagged. Linear levels, but with plenty of explorable sidepaths containing mandatory and optional items.
- Yellow Taxi Goes Vroom
- Yooka-Laylee (a Spiritual Successor to Banjo-Kazooie created by former Rare developers)
- Yoshi's Story: A rare 2D Platform Game example. Levels endlessly loop and progress is achievable only by eating enough fruit found both in the main path and side areas.
- Zera: Myths Awaken
