King Arthur's Gold

King Arthur's Gold is a free-to-play competitive multiplayer platformer, based around building structures out of wood, gold and stone in a very Terrarian style. The game plays a lot like a medieval version of Team Fortress 2 in some respects, using three basic classes. At the beginning of each round, there is a variable grace period in which most players switch to builder, and construct elaborate fortifications and traps on their side of the map. The middle of the map cannot be entered until the grace period ends, at which point both teams rush to claim it and eventually move to siege the enemy castle. The game has a basic structural physics engine; structures without any connection to the ground will fall, crushing anyone unfortunate enough to be standing in or under them. The final objective varies depending on game mode. Currently, two game modes are played with any regularity, CTF and Team Deathmatch. In CTF, the first team to capture the opponent's flag above their starting tent and bring it back to their own tent wins. In Team Deathmatch, the team who can reduce the opponent's respawn counter to zero, then kill all the remaining opponents, wins.
 * The Builder: The one who builds stuff. Can construct anything from simple stone walls to bridges that open up when enemies try to use them. This comes at the price of having almost no defensive capabilities. The builder can use his/her hammer as a weapon, but it's not very effective against either Knights, who can shield it, or Archers, who are rarely within swinging distance. Builders can dig through all blocks except bedrock.
 * The Knight: The backbone of most teams, the Knight can play well on defense or offense. They have a sword and shield as their most obvious weapon, but can also carry up to three bombs for assaulting castles or taking out tight clusters of enemy units. The shield can block arrows, sword strikes, and even bomb explosions, though that last one will knock the shielding knight back a fair distance, and the explosion will still hit others behind the shield. Knights can dig through dirt and chop down wooden doors with their swords, but cannot break stone except with a bomb.
 * The Archer: The only truly ranged class in the game, the archer uses cover and stealth as a primary method of defense. Once arrows are obtained, either by chopping down trees or buying them with coins at an arrow shop, the archer can fire arrows at various speeds, determined by how long the mouse button is held. Charging the draw meter all the way results in a powerful direct shot that can break through a shield. Archers are also capable of ducking, climbing trees, and using arrows as a makeshift ladder, adding to their ninjaesque repertoire.

Can be found here. It is currently in it's alpha stage (as of 2/17/2012).

This game provides examples of:

 * Floating Platforms: Possible if done correctly, oddly enough. Most of the time though...not so much. And god help you if you happen to be under any structure that lost all of it's support.
 * Grievous Harm With a Body: You can chuck corpses at people and use them as catapult ammo.
 * Ludicrous Gibs: Happens when hit with a bomb explosion, or when falling far enough. Basically, enough damage to kill in one hit from full health will do it.
 * You can also Gib corpses if they aren't already gibbed. Important, since they can block your path.
 * Rocket Jump: Knights can do this with their bombs.