Remember Chip's Challenge? Originally released on the Atari Lynx way back in 1989, it was later ported to DOS and Windows then bundled with Windows 3.1, which is where many players will know it from. It's a puzzle game with over 100 levels, some of them mazes, others block-pushers or enemy-dodging challenges, often with harsh time limits to complete them in.
There's a plot involving Nerdy Chip McCallahan collecting computer chips to earn his way into a high school computer club and win the affection of a girl named Melinda the Mental Marvel, but the more memorable story is how the sequel spent over 20 years in legal limbo (opens in new tab). While the first game was made in a matter of weeks, the sequel took a couple of years to complete—by which point the trademark had been sold on. Negotiations with the new owners stalled, and Chip's Challenge 2 took 25 years to see the light of day.
Chuck's Challenge 3D (opens in new tab), created by Chip's Challenge creator Chuck Somerville, was remastered earlier this year. And now the original Chip's Challenge can be downloaded on Steam for free (opens in new tab).