It is the sequel to The Sentinel by Geoff Crammond and features 651 levels, a multiplayer mode and a soundtrack (titled "Earth/Air") composed by John Carpenter and arranged by Gary McKill.

While in The Sentinel the levels were bright and colorful, in Sentinel Returns they are dark and gloomy, with flashes of light being emitted when an object is created or absorbed, and the mouse pointer dynamically lighting the world.

The game has a general "hallucinated" look: the skies are made out of contrasting streaks of color; the trees are white; the boulders pulsate as if breathing; the sentinels and sentries are hybrids of flesh and metal; the sentinel stands are covered with skin and have four vertebral columns protruding from the corners; the "specimen" representing the living part of the synthoid resembles a hydatidiform mole, and it squirms and lets out a shriek when injected with a needle.

Thus, in general terms, absorption is simply the transplanting of energy to another location on the game field.

If the Sentinel or Sentry can see a Synthoid or a boulder, but not the square it is standing on, and there are trees in the vicinity, it will transform one of them into a Meanie, which will start rotating.

[7] The goal of multiplayer mode is to race each other to the Sentinel; every player can teleport each other's synthoid to lower levels.

[7] The developers made a conscious decision not to stray too far from the highly regarded original game, instead focusing on refining the difficulty slope.

[7] At one point they planned for there to be 666 levels, and to not include the level-skipping mechanic from the original game.

[9][10] Next Generation said of the latter version in an early review, "Those who have fond memories of the original or who crave a new PlayStation experience should rent before buying.

"[23] Official U.S. PlayStation Magazine gave the same console version a negative review, about two months before it was released Stateside.