Level Failed (called Try Again in Go!, Battle Lost! in Epic, Unlucky! in Transformers, Lose in Fight!, Game Over in Arcade, and Maybe next time! in Blast!) is a common term used in the Angry Birds franchise and most other video games that is given to the player when they run out of birds/pigs/bubbles/cards/moves. Usually, they cannot continue and must restart the level, but can often load their progress.
The level failed screen differs from game to game, but the text is usually against a pig that seems to mock the player excluding Angry Birds Star Wars II on the pork side, Angry Birds Go! (current version) and Angry Birds Transformers.
There also exists non-standard level failed screens, which involve special punishments for specific mistakes.
From Angry Birds POP! onwards, failing a level will cause the player to lose a life.