Kirby flew -- or rather, drifted lazily -- beneath the radar for years. His early games did well enough, but they never seemed to foster much discussion. It was really Kirby's Adventure for NES that gave him his break into widespread public awareness... and even then, that didn't happen at the time the NES game debuted, but rather several years later once NES emulation became a widespread phenomenon and Internet nerds started picking through the system's catalog to find all the cool stuff they had overlooked.
Buried amidst janky early Famicom games like B-Wings and Nuts & Milk, a handful of largely overlooked gems found a newly appreciative audience. Kirby's Adventure was one of those games: Colorful, fun, creative. As emulation fans poked around into even more esoteric territory, however, they quickly discovered the even more surprising truth that Kirby had been around for years, having made his debut on Game Boy. You know, that system no one bothered taking seriously between Link's Awakening and Pokémon Red & Blue.
Since Kirby's Adventure (or other, even better games, like Kirby Super Star) offered many gamers their entry vector into the franchise, those old Game Boy titles tend to go tragically overlooked. Not only are they smaller, simpler-looking games, the very first one -- Kirby's Dreamland -- barely even plays like Kirby as most people think of it. There are no powers to absorb; swallowing enemies is simply a means to get them out of the way or acquire a projectile to spew at other foes. Kirby's Dreamland 2 helped properly codify what it means to be Kirby... but no one ever really talks about that one. [Note: I had originally cited this as preceding Kirby's Adventure, but that was incorrect.]
A short, sweet little platformer, Dreamland 2 adds two new facets to its predecessor's framework. First, Kirby can sometimes team up with animal pals to ride around for his adventuring; secondly, he can also steal an enemy's power by eating that foe. The former feature shows up from time to time within the franchise (most significantly in Kirby's Dreamland 3, a wonderful and also severely overlooked game from the waning days of the Super NES), usually with small differences from one to the other.
Here, each animal controls differently -- you can ride the hamster, for example, but the pigeon will carry you through the air -- and each one "processes" the various powers Kirby acquires in its own unique way. Getting used to the individual control quirks of the animal companions becomes a big part of the fun and the strategy of Dreamland 2; for instance, flying freely with your bird friend without sacrificing your offensive capabilities beats Kirby's normal mode of flight, but it also means you can't absorb powers without first landing.
And really, power absorption is what Dreamland 2 is all about. Historically, the ability to gain and surrender new skills on the fly changed the series from an incidental little bit of platformer fluff to a unique and lasting franchise. In the present, it makes for a game that remains entertaining even now. Sure, it's been outclassed by its sequels (specifically on 3DS by that keen 3D Classics remake of Kirby's Adventure, but the simplicity of the Kirby games helps them weather the ravages of time in a way that most black-and-white Game Boy releases don't. Kirby's power selection is more limited and allows fewer combinations than in later games, but that's OK. It adds just enough to Kirby's Adventure to make it interesting. And sometimes, uncomplicated design can be nice to fall back on.