I read reviews carefully before buying games and never pre-order so I've never been stuck with a truely bad game. The price of games these days is such that I'm not going to buy a game unless it's at least competent. Back in the day however there were truely some shockers.
E.T. (for the Atari 2600) - famously the worst game ever made, I didn't have an Atari so I missed out on it at the time, but a friend showed it to me a few years ago and it truely is woeful.
Pac Man (for the Atari 2600) - if you'd played the arcade version and then got this. I actually read really good book about the Atari a few years ago (called Racing the Beam) which describes how difficult it was to program even the simplist games on it. Basically the Atari couldn't draw 4 ghosts and Pac-Man all at the same time without a hack that made it flicker like crazy.
E.T. (for the Atari 2600) - famously the worst game ever made, I didn't have an Atari so I missed out on it at the time, but a friend showed it to me a few years ago and it truely is woeful.
Pac Man (for the Atari 2600) - if you'd played the arcade version and then got this. I actually read really good book about the Atari a few years ago (called Racing the Beam) which describes how difficult it was to program even the simplist games on it. Basically the Atari couldn't draw 4 ghosts and Pac-Man all at the same time without a hack that made it flicker like crazy.