The player plays as a mercenary who takes on missions around a procedurally generated galaxy in order to liberate space stations.

The nebula serves as a tech tree, allowing the player, with each liberation, to unlock various items, such as guns, gadgets, explosives, or pods.

[2] The layouts of the nebulae, the ships, their crew, and missions are procedurally generated, similar to games of the roguelike genre.

This can be done indefinitely, allowing for stunts such as picking up the weapon of a fallen enemy, equipping it, and using it against another target all while in this pause screen.

[5] After avoiding criticism of Heat Signature for two weeks after release, Tom Francis agreed with many of the caveats in the other-wise positive reviews, saying in a blog post "almost every critique I read I thought was a fair point."