This was usually a super Star Trek game, or an implementation of Life (which led to a fair number of language wars), or a 4x4x4 tictactoe or chess program. One hacker won his spurs making the best checkers program going. More complex projects were binary file editors, system utilities (magtapes pretending to be DECtapes!) or OS mods. Some were lucky to get to an hacking Mecca - these are the ancient heros. Acceptance could not be purchased, only earned and poseurs were ridiculed.
I assume things are similar now, with GitHub replacing card drawers and net based communities replacing f2f. “Because I could” was an amazing goad, particularly when you didn’t know the limitations. Cracking, while useful, wasn’t anywhere near as worthy or honourable. Hackers make neat things. It’s the making not the knowledge itself, and whether the thing is used is a secondary but satisfactory gain.
Decades on, I’ve written miles and miles of code, but very little of it was neat. Useful, commercially successful, yeah, but only a few things here and there made me sit back and smile - these things would have passed muster back then. I hope others get to experience such feelings a few times in life.