From Halopedia, the Halo wiki

This article is about the achievement. For the Forerunner, see Boundless.

Boundless is an achievement in Halo: The Master Chief Collection. It is unlocked by beating the 10,000 point par score on the level Delta Halo. The achievement is worth 10 Gamerscore. Though it can theoretically be unlocked on any difficulty, more points are awarded in campaign scoring when playing on higher difficulties.