In just about every game, you can purchase upgrades and bonuses with either in-game currencies or real money. With some of the games, you have to buy the in-game currency with real money in order to spend the in-game currency on stuff.
In Stampede Run, if you get run over you can buy up to four extensions to your run, for 100, 150, 400, and 800 gems respectively.
In Matching, you drag and drop pieces onto the board to match three or more of a color to be removed from the board.
In Gems, you drag and drop individual gems onto the board; once three or more match a color, they condense to form one gem of the next higher number.
Words With Friends
Crossover: You can pick up letter tiles from Words as bonuses in Stampede Run. Get enough to spell out a word and you earn extra gems and XP.
Advancing Wall of Doom: The three bulls that smash through the barricade at the start of the game are chasing you the whole time you're running. Stumble and one will be right on your tail for about 5 seconds. Stumble again during that time and you'll be run down.
Anti-Frustration Features: In the 2-player version, if you get knocked out before reaching 500 Ms, the game will let you restart your run.
Christmas Episode: The game got a Christmas-themed upgrade in 2013: lighted antlers on the bulls; snow, presents and snowmen as obstacles; and Christmas-themed signage on the vehicles, sawhorses and roadblocks.
Collision Damage: Running into a small obstacle or runner without a take-out move will cause a stumble instead of knocking you out completely.
The Juggernaut: The Bull Ride bonus lets you jump on a bull's back and go plowing through obstacles that you normally would have to avoid.
Jump Physics: You can move around while jumping just as while running; you can even turn corners while in midair. Dropping early on jumps is sometimes necessary to pick up stars and/or avoid or break obstacles, and moving while in mid-air can get you to raised areas to get stars and bonuses.
Rewarding Vandalism: Breaking small obstaclesnote sawhorses, barrels, traffic cones, boxes, hay bales, and broken watermelons in your path will earn you stars. In many cases you'll earn more stars by breaking stuff than by simply running through the tracks of stars that avoid the obstacles, especially if you purchase a bonus before the 2-player game starts and especially in the single-player version if you've purchased/upgraded your permanent boosts.
Score Multiplier: Jumping off bulls' backs in succession will increase the points you earn for each jump.