I'm new here, despite the forums being seemingly a ghost town, but I don't know how to get thoughts on minigame ideas, because I cannot think of a proper place to discuss, since general opinion suggests that Mario Party is just a small piece of the shell of its former glory.
Anyway, the ideas I have are mainly 2vs2 minigames. The main gripe I have with some 2vs2 minigames is that some in concept feel like 4 Player minigames split into two teams. (Bus Buffer and Sphere Factor). I always preferred minigames where each member has a different role, as you would really need to rely on your teammate (Handy Hoppers, Jump the Gun, and Boo Burglars)
Stretch Goals:
This minigame takes place on the ramp of an airship, in which for each team, a rope is tied between the two members (similar to Rope or Dope). The game consists of a simple grab x, dodge y objective, where you grab coins and dodge Spiny Eggs that roll down the ramp. The main catch is that if you and your teammate move too far apart, the rope would pull and snap you two together, making your team lose 10 coins and get "dizziness", making it so that you and your teammate must stay and move closely together when collecting coins.
Baller or Faller:
This minigame is a simple race to the finish between the two teams, with the usual obstacles. The main gimmick is that for each team, one player is inside a hamster ball, while the other is on top of the same ball. When racing, the player inside the ball is the one in main control to the finish line, however as the ball is moving, the other player must try to keep balance and not fall off. If the player on top does fall, a penalty would be made where the fallen player gets dizzy for a while and automatically jumps back on the ball before the player inside can move again. The ball can move faster with better momentum which would be more quick, but also more difficult for the player on top to not fall off.
Fire Fighters:
The two teams enter a temple room filled with 7 lanterns lit with red fire, and 7 lanterns lit with blue fire. For each team, one member has a torch with either red or blue fire, while the other has a bucket of water. The gameplay is similar to Tile and Error where the lanterns with the most of the team's colour wins. The player with the torch lights up lanterns, while the player with the bucket extinguishes them.
Rally em Up:
This minigame consist of the duo within a team facing against each other on a table tennis table. However, rather than playing traditional table tennis, each team must gain points by performing a rally. A point would be gained per successful return, and after each 10th return of the rally, the points earned per return will increase by 1 (2 points per return after 10, 3 points per return after 20). As the rally continues, the ball would become faster making continuing the rally more difficult. If one player fails to return, they would have to restart the rally.
Backlight Fright:
For each team, the pair is inside a laboratory-like room, when suddenly the power runs out and the room is suddenly pitch black, as well as haunted by Boos. To regain power, one player goes to a GameBoy like device in the centre of the room and must complete a series of three platforming challenges (similar to Lift Leapers) where the first team to restore power wins. However, for the game to be visible and playable, the other player must shine a flashlight at the device.
This would be simple, however, Boos would also try to attack the device which would restart the games's progress at the current section. To prevent this, the player with the flashlight must stop shining at the device, (which would prevent the game from being visible) and traverse the room and kill nearby Boos by shining their light at them. As the room is pitch black, Boos present in the room are not visible, leading to the flashlight player to decide if they should make sure the room is currently safe or allow the other team member to progress.
Bat to the Bone:
This minigame involves the two teams on a baseball field at the same time. One player has a baseball glove and a Koopa shell of their team's colour, while the other player has a baseball bat of their team's colour. To win the game, the pitchers needs to aim their shell to allow their team's batter to hit the shell, scoring the team 1 point. To retrieve the shell, the pitcher must jump on the moving shell to stop it, before picking it up, otherwise would make the team lose a point if hit by a moving shell. The pitcher can also aim their shell at the opposing team members, making the other team lose a point when hit. The batter can defend themselves by hitting the opposing team's shell (which won't score any points) while the pitcher can stop the opposing shell by jumping on it. The team that goes to five points first wins.
Panel Channel
This minigame involves red-blue panels (The red and blue panels from Galaxy and 3D Land and World which switch when you jump), where each team must race to the finish, but must co-ordinate jumps as panels would switch every time someone on the team jumps. (Basically that one level from 3D World full of these things, making multiplayer on it chaotic).
I'm not expecting many replies due to how often someone posts here, but feel free to comment if these ideas can be improved or your thoughts or them, or perhaps ideas of your own.