Here's a game that I thought of and would love to get everyone's opinoin.
TNT RUN
How it works:
How the game works is there is one big arena with pressure plates. Under those pressure plates is gravel/sand or any collapsible block and under that block is TNT. When a pressure plate is stepped on by the player stepping on it will cause the TNT to fall and remove that block from the arena. Eventually players will have a very small space to run, therefore causing them to fall once a player has fallen out of the arena they are out.
Through past experience on playing this game on other servers it has caused lag for some players. But the lag is usually minimal and sometimes unnoticeable.
Feel free to ask any questions about the game and I will gladly answer!