Battle Ring (Wario World)
From the Super Mario Wiki
Battle Rings are small fighting arenas that Wario encounters during the events of Wario World, starting to appear in Greenhorn Ruins. Every level thereafter contains at least one Battle Ring, while Shivering Mountains and Beanstalk Way. Upon entering a Battle Ring, which are always circular in design, a force-field will surround it, trapping Wario inside. Various enemies from the level appear from nowhere and ambush the anti-hero. Wario must use his various attacks to survive for 60 seconds.
Some columns will always be inside the Battle Rings for Wario to use as weapons. After the 60 second time limit is up, a wooden chest appears, containing some coins. The more enemies Wario defeated in the sixty second time limit, the more coins he receives. Wario is then allowed to continue on his journey through the level.