I made a mini game in Minecraft, it is a archery range, you have to shoot the targets to continue to the next target, there are in total 6 targets to hit, if you hit a target you get a diamond, you can play the game again by stepping in the hole and pressing the button, this will kill you and you will spawn by the bed again, there are about 60 diamonds in the dispenser.

The mini game is server compatible as far as I know.