It was an instant classic way back when, and with good reason!
I’ve recently picked up the Game Boy version (the very first!) on emulator, and boy is this game deep! There’s a lot more to the gameplay than initially meets the eye, and the whole thing seems to be set up to attract people like me: Stack the blocks up as neatly as possible and score big by clearing four rows in one go, which is oh so satisfying. Nice and orderly, eh?
A lot of variations have been brought up over the years. Many different game-modes and features have been added, removed, changed and thrown around like nobody’s business. Multiplayer was already in the first iteration, which was a great touch. Other common additions include quick-dropping (instantly letting the piece fall into place, which makes for a speedier play experience), piece holding (allowing you to store a piece for later use, which is generally used for easier access to line blocks, easy-mode), and I’ve even seen piece shadows (where a transparent version of the piece is shown at the location it’ll land) which in my opinion is just plain ridiculous. There’s also versions that add gravity to the blocks so they fall down when there’s nothing under them (stupid!), and others let you see more than one piece in advance (only becomes an important factor in higher levels of play, but can make things a lot easier).
I find it really cool how easily extendible Tetris’ gameplay is. And even without all the bells and whistles there’s already a lot of depth to the game! Once you get good at stacking your pieces up nicely, you can start taking the next available piece into account. Building nice structures for that? Cool, now how about clearing lines or even leaving empty spaces for the sole purpose of setting up more comfortable block placement later on? Hey, are you managing to clean up your mistakes neatly? Are you going for the highest possible score yet?
All that seems to go out the door once you hit level 9 though, at least when you don’t have lightning fast button pushing fingers.