The game's second half features mechanical puzzles and traps using machinery, electromagnets, and gravity. Many of these traps are not apparent until triggered, often with deadly consequences. The player is able to restart at the last encountered checkpoint, with no limits placed on how many times this can occur. Some traps can be avoided and used later in the game; one bear trap is used to clamp onto an animal's carcass, hung from the end of a rope, tearing the carcass off the rope and allowing the branch and rope to retract upwards and allow the boy to climb onto a ledge otherwise out of reach. As the player will likely encounter numerous deaths before they solve each puzzle and complete the game, the developers call Limbo a "trial and death" game. Some deaths are animated with images of the boy's dismemberment or beheading, although an optional gore filter blacks out the screen instead of showing these deaths. Game achievements (optional in-game goals) include finding hidden insect eggs and completing the game with five or fewer deaths
