Now you might be thinking that it would be pretty much impossible to control 50 avatars simultaneously -- and you would be right. In fact, your little Swarmites are constantly dying off due to traps, environmental hazards, and good old-fashioned failed jumps. Not only is this okay, it's necessary; each death increases your score multiplier, and interesting deaths result in in-game awards. Swarm tasks players with getting a gaggle of 50 creatures across dangerous levels, into what looks like a giant elephant trunk. Along the way, there are land mines littering the floor, chasms, Mario-style lava fireballs, and other hazards. It's not enough for your errant creatures to fall in the lava, by the way; when you miss a jump, spikes fly out of the lava and impale the unlucky Swarmites. At a few points during each level, you can replenish your supply of Swarmites using "DNA" piles, which is important for two reasons; first, if you run completely out, you lose, and second, because you need multiples both for basic gameplay and to hit pressure pads that give you bonus items.
Your Swarmites all move in unison in response to the analog stick, and jump in near-unison. You can also make them gather or spread out. Combining these moves allows you to do things like make them dash to break objects (which always kills a few Swarmites) or jump on each other's shoulders and form a tower. That last move is used to create a sort of "human" bridge from one platform to another, and to knock over stacks of crates.
In most games, you would attempt to get through each setpiece without killing your characters, but in Swarm, you have to, and should.
The literally disposable nature of the Swarmites is what gives the game its hook. In most games, you would attempt to get through each setpiece without killing your characters, but in Swarm, you have to, and should. The game requires certain score quotas for completing levels, meaning you have to get a score multiplier going and keep it up. And that means steadily killing off your dudes -- not that you really have to be too strategic about it, at least in the early levels I played. They'll kill themselves just fine.
In addition to multiplier-focused killing, sometimes the Swarmites have to sacrifice themselves. One scene required me to toss bombs at a wall to drop it down and make a bridge. Some Swarmites picked up bombs, and others picked up ... other Swarmites. In another scene, you force Swarmites into some kind of exhaust vents to destroy a machine in your path.
Now that I think about all those innocent little guys, I feel kind of bad for enjoying myself.