In every other game you have ever played, achievements are decoration. You do the thing, and a little box tells you that you did the thing. Achievement Unlocked 3 takes that arrangement and inverts it completely: there is no score, no boss, no level to beat. There is a blue elephant, a building full of rooms, and 400 achievements to unlock. That list is the objective.
It comes from jmtb02 โ John Cooney โ published by Armor Games, and it is the third and largest entry in one of the most-played comedy series of the Flash era. The elephant is his signature character, the writing is very funny, and the whole thing is built to make you laugh at how willingly you are chasing a checklist.

The genius of the series is the ladder. At the bottom are achievements so trivial they are insulting โ you get one for jumping. You get one for picking up a coin. You will have unlocked a dozen before you have consciously done anything.
Then it climbs, and keeps climbing, until you are doing things like firing a hamster through a basketball hoop, or running on a treadmill while on fire, and it dawns on you that you are not being rewarded for playing well โ you are being rewarded for being curious and stupid in specific ways. Every weird interaction you can think of has probably already been anticipated and given a name.
That is really the design: the achievement list functions as a to-do list written by someone who has thought of more dumb ideas than you have.
This deserves its own heading because it reverses the instinct every other platformer has trained into you. In Achievement Unlocked 3, death is frequently the goal. Plenty of achievements are only obtainable by getting the elephant killed in a particular way, in a particular place, or a particular number of times.
There is no lives counter and no punishment. Once you internalise that walking into the spikes might be the correct move, the game opens up enormously โ and it is a genuinely liberating feeling to play a platformer where you are actively hunting for ways to die.
The first two Achievement Unlocked games were deliberately minimal โ stark visuals, a single room, the joke delivered fast. The third one is far more ambitious, and if you only know the originals it will surprise you:
The map is a collection of gloriously unrelated spaces, each existing mainly to generate a category of nonsense:

For something whose premise is a punchline, AU3 carries a startling number of real mechanics. There are torches to light, and separate water and fire meters โ your elephant can catch fire and can get thoroughly drenched, and the two states interact. There is clothing customisation. There are portals. There are buttons that spawn hamsters. And there are dead elephant corpses lying around that you can interact with, which tells you most of what you need to know about the tone.
None of these systems exist to be deep. They exist because each one multiplies the number of ridiculous combinations the achievement list can ask you for.
Worth being honest about, because it is the most interesting thing about the gameโs place in history. When the first Achievement Unlocked appeared, the satire was sharp: it was mocking an industry that had started handing out trophies for pressing start. By the time AU3 arrived with 400 of them, contemporary reviewers noticed something awkward โ 400 achievements had stopped being an absurd number and become merely a large one. Real games had caught up with the parody.
Which does not make it less fun. It just means AU3 works better today as a very well-made comedy platformer than as a critique, and reviewers at the time said as much: "massively entertaining", "pure gaming joy", with the satirical edge somewhat blunted by the world it was mocking.
If what you enjoyed was a game that is quietly commenting on you while you play it, Getting Over It with Bennett Foddy is the other great example of that โ a narrator talking about failure while you repeatedly fail. And if it is the compulsive checklist itself that grabbed you, AdVenture Capitalist is the same instinct pointed at a number instead of a list.
No download and no plugin needed โ load it up, jump once, and collect your first achievement about four seconds from now.