Spiral Knights

Spiral Knights is a massively multiplayer online game that Sega formerly published before selling the rights in 2016 to Grey Havens, a company made up of former members of the then defunct Three Rings Design subsidary of Sega.

Plot
The Spiral Knights are a spacefaring army from the planet Isora.

Their ship, the Skylark, has crashed on the planet Cradle. The interior of the planet is filled with a mechanized, continually reconfiguring dungeon called the Clockworks.

Operating out of the town of Haven on the planet's surface, the knights descend into the Clockworks, with the goal of understanding the mysterious energy source at the planet's core.

They hope to exploit this energy source to resurrect and re-launch the Skylark.

Gameplay
Players play as a tiny customisable Spiral Knight who will quest into the Clockworks alongside up to three others in a party. There they must fight monsters, dodge traps, and team up to take down large groups of enemies and unstoppable bosses.

Spiral Knights can use swords, hand guns(for those who prefer long range), bombs and shields and their helmets, armor, accessories and trinkets are all interchangable allowing users to create their own unique look.

For more details on this game, we recommend checking out the Spiral Knights Wiki.

Sega costumes
Spiral Knights had some Sega themed outfits.

To celebrate the Sonic CD re-release in 2012, Spiral Knights released an accessory titled 'Tails Tails' which gives the Spiral Knight a set of Tails' iconic tails.

A helmet and armor set based around Metal Sonic was also released around this time.

These items were unavailable after Sega left the game, but it is still possible to obtain these items via online trading. However, their worth skyrocketed after the split made them highly sought after rare items.