PopCap latest installment in its Plants vs. Zombies franchise was a bit unorthodox, to say the least. Rather than follow up with yet another dose of reliable lawn-defense action, the studio decided to create an action-packed shooter, in the style of a Battlefield or Call of Duty. It’s just the most recent in a long line of head-scratching experiments and mashups that game developers have dabbled in over the decades. Whether it's a surprise left turn from a well-known franchise or a bizarre partnership, we take a look at some of the strangest examples we could think of. Let us know if we missed any of your favorites in the comments.

Kingdom Hearts
Square had experience in merging a well-known property with its own RPG sensibilities thanks to Super Mario RPG. It’s hard to imagine that anyone could have guessed that the company could manage to build a game featuring Mickey Mouse, Goofy, Donald Duck, and a host of other Disney characters. The game took players on a memorable journey through worlds based on The Little Mermaid, Winnie the Pooh, and more. 

Super Mario Kart
Mario and Bowser go way back, but they typically settled their differences in high-stakes battles. Friends don’t typically dunk one another in fiery moats, after all. The duo was able to set aside their differences and compete in less lethal ways with the introduction of Super Mario Kart. Nintendo expertly took familiar elements from the Super Mario Bros. games and put them into one of the most beloved multiplayer series out there. Even though Mario and Bowser could call a temporary truce, the games have put more than their share of friendships in peril.

Super Smash Bros.
Sometimes a friendly race around the track doesn’t cut it. Super Smash Bros. took Nintendo’s roster of characters and pit them against each other in not-quite-mortal combat. It seemed ludicrous at the time, but in the best way possible. Finally, Peach could get Mario off her back by using a frying pan to knock him offscreen. Donkey Kong and Yoshi could team up and wipe the smile off that smug little Kirby? As wise men once said, there’s a fine line between being clever and being stupid. Super Smash Bros. toed that boundary with style.

Lego Star Wars
Traveller’s Tales has turned games based on Lego’s toy lines into a cottage industry, releasing new installments on an annual basis. They’re so ubiquitous now that it’s hard to imagine that there was ever a time when they didn’t exist. Lego Star Wars: The Video Game was possibly the only good thing to come from the new trilogy. They showcased the humor, action, and co-op that been foundational to each of the games that the studio has released since. 

World of Warcraft
Blizzard didn’t invent the MMORPG – not by a long shot – but it helped to bring the genre mainstream with World of Warcraft, thanks to easy solo play and a user-friendly UI. At its peak, the game had more than 12 million subscribers. Not too bad for a game based on a series of real-time-strategy titles.