With Season 3's mid season patch that came with Nubla as a new character, there is also a bunch of new modes added. One of these is Wacky Weekends. This mode is like the Silly Quene from the Open Beta where it will randomly give you a different gimmick to the fight instead of the standard 2v2's. Some of these are actually based off Rift Nodes like Hammer Time, Ice Trap, Retro Horror and Volleyball while having new ones like Tiny vs Giants, Chicken vs Ice, Splat, Counter and much more.
These are only available to play on the weekend, hence the name so every Friday, Saturday and Sunday will have this available to play. They did release it early for a day to allow players to see what this mode has to offer and well, it can get chaotic extremely quickly with the certain character duo, how good they are and the mode itself can bring.