Can you get punished for cheating on a single player game on steam?

Games on Steam should tell you on their store page if VAC is enabled. CSGO for example shows this:

If you don't see this, then you likely won't get VAC banned. Looking at Heat Signature, it does not appear to have VAC enabled.

There are some games that "punish" the player if they cheat (look at Stanley's Parable), but if it's a singleplayer game there is no reason for contacting the server to check if your files are legit and ban you if not. Unless that there is a online leaderboard or something like that.

If you are still unsure planning on cheat don't try to use any online feature of the game. You can even block the game from contacting the internet to be sure.