Battlecruiser 3000 AD: I loved Wing Commander and always wondered what it would be like to control a capital ship like the Tiger's Claw or a Fralthi, and this seemed like the game that would make that dream come true. I ended up playing the most polished version, Universal Combat and it was still a pile of shit: Combat was a nonsensical mess where you could not tell how much damage you were taking or inflicting; traveling between systems often took ten minutes; the interface was a nightmare that made most flight simulations look simple and convenient; it crashed constantly; and despite the frustrating combat, it was a Roguelike.
Outpost: A promising simulation in which you had to rebuild human civilization on a new planet. It sounded like an interesting, complex game, but turned out to be a slow, buggy, unchallenging, overcomplicated mess that was quickly forgotten.
Mario is Missing and Mario's Time Machine: Turned one of the greatest game series into a slow, boring mess with no action, no creativity and nothing to do but answer trivia questions.
P.C. Mega Man 1 and 3: Mega Man is a fast, fan, colorful series, but you would never know it from these slow, unplayable, impossible games.
Jurassic Park: Trespasser: It promised to have a unique control system, a complex open world filled with cool dinosaurs and a lot of innovative puzzles. It ended up with nonfunctional controls, a featureless world with only a handful of dinosaurs because the game ran slow as shit even with those compromises and poorly-designed puzzles.
Darklands: It could have been great, as it had a great style inside towns, but the combat seemed to be unaffected by the player's choices and wandering around the open world was boring.
Albion: It had a lot of style and imagination--too bad the horrible controls and the fact that the doors looked like the windows made navigating in third person impossible, first person was even worse and the combat was a mess.
Gabriel Knight: The Beast within: A sequel to my favorite adventure game. Gabriel Knight was very atmospheric and mysterious, had great puzzles and characters and a nice sense of humor. This sequel was set in a boring city, had boring characters and a languid story, easy puzzzles and took itself way too seriously.
Darkwing Duck: Capcom made a lot of great games based on cartoons in the NES and SNES days, like Chip and Dale, Ducktales, Little Nemo and Aladdin. This, however, was a dull gamme with poor controls, level design and hit detection. I would have thought this was a bad Mega Man ripoff if I was not aware that Capcom made Mega Man.
Space Quest 6: Turned a classic series into a boring mess with little humor, poorly designed puzzles and an abrupt ending. This was the last official entry, though the fans made excellent sequels: Vohaul Strikes Back and Incinerations.
Daikatana: It should have been a great fast-paced shooter like Doom, but instead it was a frustrating mess in which you could be killed by your own weapons and had to babysit two retarded teammates.
Contra: Legacy of War: Took a classic series and turned it into a wretched pile of shit where it was nearly impossible to avoid taking damage, kill enemies or do anything.
Castlevania: Lords of Shadows: Turned a classic action series into an incredibly boring and tedious game whcih dragged on endlessly.