It's the strategy in maze building tower defense games where you sell a tower at the beginning of the maze then seal off the end of the maze to force the units to repathfind the huge distance back through the maze for an easy win. Depending on the complexity of the game and spawn rates it's more difficult to pull off. There are TD games that assume you'll cycle the start and end of the maze multiple times to kill a boss.

It's the strategy in maze building tower defense games where you sell a tower at the beginning of the maze then seal off the end of the maze to force the units to repathfind the huge distance back through the maze for an easy win. Depending on the complexity of the game and spawn rates it's more difficult to pull off. There are TD games that assume you'll cycle the start and end of the maze multiple times to kill a boss.

D: That explains a couple of games I've run into being "impossible".