Trials

Trials is a series of videogames made by Finnish company Red Lynx based on the sport of, well, trial. Your goal is to ride your bike from point A to point B in a 2D track (which is everything but plain and straight). Has several releases:

Trials Basic (Java)
Trials Pro (Java)
Trials Construction Set (PC)
Trials Mountain Heights (PC)
Trials HD (XBLA)
Trials 2: Second Edition (PC)
Trials Evolution (XBLA)

Tropes used in Trials include:

2½D: Trials HD, while fully rendered in 3D, are limited to 2D tracks, with only forward, up, down, and back being the only directions the player can travel. Trials Evolution plays with this a bit, as the 2D track itself can turn left or right, but the player is still restricted to the plane of the track.
Air-Aided Acrobatics: Certain levels in Trials HD feature fans that levitate the player. One level in Trials Evolution features pipes that shoot a burst of water/air and launch the player.
Character Customization: Introduced in Trial Evolution through a cash-based system. Players earn cash by completing tracks and can spend the money on unlocking different clothes and (purely cosmetic) equipment. Previous games also allowed the player limited color customization.
Check Point: Each level features many Check Points, usually placed right after a difficult segment.
Difficulty Levels: In Trials HD, tracks are rated Beginner, Easy, Medium, Hard or Extreme.
- There's also Ninja dificulty, one step above extreme. Fan created, but is now an offical tag.
Everything Explodes Ending: Trials Evolution features the player humorously exploding in some way at the end of nearly every track.
Fake Difficulty: Averted. All the tracks are possible using the correct bike. Still, some are quite tricky...
Floating Platforms: Averted for the most part, though certain levels (such as the "dream" level in Trials HD) still feature them. The player can also create floating platforms in the Level Editor; there's no requirement that they be supported.
Level Editor: Trials HD includes one, and Trials Evolution added a major upgrade that includes the ability to curve tracks, a 3d open sandbox, and it's own visual scripting system.
Platform Game: While the game is mostly about riding from point a to point b, there are often elements of platforming. Some sections require skillful use of balancing and throttle control to bunny hop from one platform to the next, and others may involve the player having to ride half-way up a loop and then land backward on a suspended platform. Trials Evolution also features some track elements that swing, move, or are generally unstable.
Ragdoll Physics: In Trials HD and Evolution, whenever the player crashes.
Scripted Event: Some of the more fanciful tracks have elaborate scripted events that trigger when the player passes a certain point.
Sequel Escalation: Every game before Evolution took place in a generic warehouse. Evolution features levels set during the Normandy landings and a level based on Limbo
Sidetrack Bonus: On certain tracks, at the very start, the player can find little Easter Eggs if they go backward instead of forward.
Side View: Averted. Though the gameplay is 2D, and the view is always from the side, the camera occasionally will dynamially swing around or will rotate slightly at certain points in the track, such as if the player is making a huge jump or outrunning an explosion.
Springs Springs Everywhere: The game features fairly realistic physics, such that the player can easily hop their bike around with the right combination of balancing and throttle, and landing wrong on a ramp might cause the player to bounce wrong and slow way down (or crash). Trials Evolution also added many new track elements that can bounce players, such as pistons and logs bobbing in water.
Stuff Blowing Up: In ludicrous amounts. Many tracks have explosive barrels or TNT in certain areas that the player must avoid.
Time Trial: Each track has a certain time you must beat in order to win a Gold, Silver, or Bronze medal. Also, how players are tracked to see how they stack up against each other.
Totally Radical: Trials HD and Evolution intentionally play up the "extreme" aspect of the game. Trials HD begins with over-the-top rock music and an announcer with a rock star voice spouting stereotypically "extreme" statements. Evolution begins with the same announcer rapping.
Trial and Error Gameplay: Particularly difficult tracks run into this; unless the player gets extremely lucky, completing a track fully, without any faults (crashes) can require many replays.
Vent Physics: See Air-Aided Acrobatics above.