One of my ideas (you can take it) it's called a Nether Speedrun (idk the name):
-Make a Nether portal at spawnpoint, then, /tp to a random location in Overworld
-Create another Nether portal, enter and place a loadstone w/ ⁓8 compasses (numbers of players). Then go in Survival and /kill to return to spawn point and Nether portal.
-Give a loadstone compass to each player; equip you in creative mode. There my rules:
1. Max 8 enderpearls 2.No elytra 3.Max 3 enchants on each object 4.No netherite, and the only dimand you can take is the pickaxe and the sword/axe for killing mobs 5.can take 3 strider egg 6.Can use all the ressources you gain in the Nether. 7. Active /keepinventory
The first player to the other portal (marked by a loadstone in the nether) win the game!!
Hope you like 
I'm searching ideas to create minigames...You can share here and I'll comment you idea.
*I'm not very good with command blocks + I'm Bedrock on PS4*