Strategies

The Swing
Push it - Push the swing into other players to clear the way or knock them off the map.

Stop it - When a player is in the swing and while the swing is moving, slowly bump into it to stop it. Keep doing it when necessary so that the player has no chance to move the swing. Right before the platform beneath disappears, jump into the swing.

Knock them out from under - If a player is in the swing, jump underneath with the right timing and enough force to knock the player out of the swing.

Knock them out from the side - Continuously hit the side of the swing with as much force as possible until the swing flips and the player falls out the swing.

Wait until the end - Let players go in the swing. Right before the platform below disappears, jump into the swing.

Moving Obstacles
Use it as protection - Get behind or near a moving object. The other players will bump into the object killing themselves.

Use it to attack - If there is a moving platform, jump in front of it and let it propel you toward another player. The platform will give you a lot of force and speed, knocking another player off the map faster than you can.

Movement
Fake out jump - When players are charging toward you aggressively and there is an edge or dangerous object behind you, jump into the air and watch as the other player falls off or hits the object.

Pong Maps
Use the ramp - To hit the ball easier and with more force, jump on the ramp behind you on any pong based map to propel yourself in the air first before hitting the ball.

Push the platform - If the player has hit the ball on your side and the platform above you is moving slowly, you can jump up on top of it and push it back. The ball will exit the hole and move back toward your opponents side.

Using The Arena
Walls - Instead of directly striking another player, bounce into a wall first before hitting the player. This does two things: 1. add more force to the strike due to recoil from hitting the wall first and 2. catches the opponent by surprise. Some exceptional players can ricochet off two or even more walls before making a clean hit.

Slopes - roll down a slope before bumping into another player. The steeper the slope the better. You gain more velocity from rolling down the slope which adds more force to the final strike. Be careful if there is an edge at the bottom of the slope. If the slope is very steep be absolutely certain you will land a good shot.

Moving platforms - hit them hard while players are standing on them and quickly go to a different platform while they fall to their demise