Sequels are an inevitability in today's media, with Activision as a prime example proving there is money to be made, as long as companies are mining the hills of fandom in the right place.
For the most part, sequels are healthy to have around, keeping the lights on at studios and giving audiences more of what they want - more of the same, but with a couple new mechanics added, plus a fresh coat of paint.
However, through the years, publishers and developers alike have tried to slip one or two horrible examples through the cracks, with them being mere shadows of their former selves. Basically, some cooking the books looked at a handful of income charts and decided "We should add THIS. Then it'll sell millions!"
As ever, many poor unsuspecting customers and fans alike fall for these trappings, coming out the other end with a sour taste. The results can even kill entire franchises, and these are some of the worst offenders out there.
10. Dungeon Keeper (iOS)
If there was ever an award for "game that's a none-game", it would go to Dungeon Keeper on iOS. The original was developed by Bullfrog Studios for the PC, and wasn't ashamed of what it was trying to be. There was no good reason for what the player was doing other than to conquer the underworld by any means necessary, and we did so in glorious, top-down base-building form.
On iOS, Dungeon Keeper is nothing more than an app designed to hoover up money from the unsuspected people that might be so unfortunate to download it. Playing means you need to resist the urge to purchase the ability to speed up arbitrary timers, though there's probably someone with endless disposable income that bought their way through regardless.
Unfortunately, this will more than likely be the last game in the Dungeon Keeper series, though it likely did cause other companies to spin their properties off into mobile ports (just look at Command & Conquer).