That is pretty normal. Operation Flashpoint cranked up bot accuracy to full aimbot levels if it detected the DRM check was bypassed. Serious Sam 3 added an unkillable scorpion enemy. One of the Ghostbusters made ghosts unkillable. And so forth

That said: My understanding is more that the way the DRM check was bypassed meant the secondary check (whenever a starmap was loaded) errored out because the function was missing.

There have been a few famous (or infamous) cases of game devs adding crack checks into their games. Basically, the devs recognize that cracking is inevitable. So instead of trying to make harder and harder DRM methods, they simply started including checks to see if the player was using a cracked copy. If they did, they could change the game in some way. This can actually be fairly effective for the reasons you mentioned: A cracker gets the game to boot, and maybe plays the first five minutes or so. Then they send it out the door without actually verifying anything further. Because they’re rushing to be the first, so they won’t bother doing a full playthrough to ensure everything works. So when the player gets ahold of it, they’re the ones who experience all the issues.

Spyro 2: Ripto’s Rage, for instance, made the game increasingly frustrating to play. It would start removing treasure you had already collected, so you had to recollect it. And in a game where your progress is tracked via collections, that means it’s a huge time-sink. And if you somehow managed to get all the way to the final boss, the game would crash and delete your save so you had to completely start over.

Game Dev Tycoon is another example. The devs themselves actually posted a “cracked” version of their game on day 1. So all the various sites grabbed it and started seeding their torrents. It’s a game where you spend time and money developing games. And the cracked version also includes a piracy feature, where as you gain popularity you also see your profits getting eaten by piracy. And the game will slowly ratchet up the amount that you lose to piracy, until it’s eventually impossible to make a profit. Notably, there was no in-game way to combat the piracy or stop it from eating into your profits.

That latter example was used to great effect, because it sent all of the pirates to the steam message boards, to complain about piracy in their games and ask if there was a way to develop DRM to combat it. In essence, they were tricked into ratting on themselves. Because if you were playing a legit copy, you wouldn’t have any issues with piracy.