Sig.NULL is a puzzle adventure game developed by SaintHeiser. It is a remake and expansion of an earlier PuzzleScript game, Signal. The game is available on Xbox One and is a full version with a license.

The game features a non-linear narrative with a dark and mysterious cybernetic atmosphere. It has an intriguing storyline that will keep you engaged throughout the game. The gameplay is centered around puzzle exploration, which will require you to use your wits and skills to solve the puzzles and progress through the game.

What makes Sig.NULL stand out is the level design, which is such that your ability to fully comprehend and exploit the rules shifts radically over time. The basic mechanism through which you interact with the puzzles works differently than you could have intuited. There are at least five revelatory moments, and each delivers a nice little jolt of discovery and recontextualization.

Overall, Sig.NULL is an excellent puzzle adventure game that will keep you engaged for hours. The non-linear narrative and the dark and mysterious cybernetic atmosphere will keep you on the edge of your seat, while the challenging puzzles will keep you coming back for more.