Barrel done and released in RTB. PM'd the add-on to Port.
Edit: I think Port needs to make a thread in modification discussion. For the frog obstacle courses the duck player type is perfect. Here's a little something I made. I can make them in any size if needed.



Edit2: Ideas. Perhaps we could expand to other party games too, not just Wario Ware? Block/Blocko Party anyone?
Collect golden bricks!
Player needs to collect 1-4 golden bricks that are randomly thrown into the playing area under X seconds. To increase difficulty timed bombs (2-3 second delay?) are also thrown into the area that have a small explosion radius.
Some sort of painting game where players are divided into 4 teams. It would neat if it was one person per color but it needs to account the possibility oh +16 players. The idea would be to color some objects with the color assigned to the player. Perhaps a large brick canvas that is colored with paint bombs? The player who colored the most objects gets a point.
Score a goal! / Defend the goal!
I don't really know how this would work with many people. Perhaps dividing the player into two teams with a 1:3 ratio? The goal keepers get a point if no soccerball enters the goal. The players get a point if one (or more?) soccerballs enter the goal.
Score a basket!
Players are given a basketball and they need to score 1-6 baskets under a time limit to score a point.
Avoid the bombs!
Several insta-kill radius bombs fall from the sky to a closed playing area. Survivors get a point.
Maze!
A smallish dynamically generated maze (I think Truce or Kalphiter had an add-on like this.) with a few minute time limit. After the first player has finished the maze others have 10-30 seconds until time runs out. Point is scored when the maze is finished.
Day 2 edit: I'll just keep stretching this post because I don't want to triple post. More ideas!
Don't fall!
Players need to cross a rope between two skyscrapers. At random times wind blows from either left or right indicated by an arrow that appears on the screen. Players have some time to move sideways (Player does not actually move sideways as not to fall off the thin brick. Sideways movement disabled.) against the wind or they fall down. Those who made it to the other side within the time limit get a point.
Ban all the noobs! / Escape from Badspots! / Capture crazed person!
Blockland equivalent of the ghost microgame in TF2Ware. Players are divided into three teams. The Badspots are given fake Ban Hammers that kill instantly. Their goal is kill all the noobs while running from the Cyber Police. The Noobs are tasked with avoiding Badspots until the timer runs out. They have three lives. (Because the Ban Hammer insta-kills) The Cyber Police's goal is beat all Badspot's into submission with their batons. (Not insta-kill) Team Badspot gets points (Perhaps this should be a Boss Round?) when all Noobs are gone. Team Noob gets points if any one of them is alive after timer runs out. Team Cyber Police gets points if all Badspots have been killed.
Whack-A-creep/Noob / Escape the Cyber Police!
3 players are scaled 2x and move slowly. They are given huge special hammers that flatten and insta-kill. They are to kill all the little creepbears (Scale ~0.5?) or alternatively Noobs. creeps get points if any one of them survives after timer runs out. Cyber Polices get points if all creeps are dead.
Hug cuddly noobs! / Avoid the creep!
Cuddly Heavy from TF2Ware. 3 players are selected to be the creeps (Slow, somewhat large) (All black player with the rapeface.) and they need to touch all the noobs. (Or some other character) Once all noobs (Smallish, fast) are dead the creeps get a point. Noobs get a point if anyone is alive after timer.
Dodgeball!
I've hosted quite a few dodgeball servers and every time each round has been really fast paced and fun. It really gets you on the edge of your seat. This could be a regular round. Each player is given an insta-kill dodgeball and the players alive after timer are given a point.
Deathmatch!
Regular deathmatch except weapons (Gun? Akimbo?) insta-kill to make the round end faster. Survivors get a point after timer runs out.
Roll the barrel!
Players need to roll a barrel 16-32 bricks to the goal within a time limit.