I recommend you post your suggestion here. This way people can up-vote and comment their thoughts on your suggestion for a better chance of it getting added.
My opinion: Although mini games are fun and all. I don't think they would be a great fit for Manacube. Manacube focuses more on community based game modes and mini games don't usually have that.
There used to be Skywars on Manacube but it quickly died because it wasn’t fit for the community. I as well don’t think it would be a great fit for Manacube as it focuses on more competitive, dedicated gamemodes.