Straima | Mythic Sword

Summary pulled directly from Steam - Some text may only be applicable to Steam platform

Straima is an arena pulse-pumper platformer for 1-4 players, featuring a level editor.

Master over 125+ devilishly difficult levels in your ravenous pursuit of pinky delicacy, spanning worlds, special powers and gameplay mutators. There's also several other game modes to enjoy, including Deathmatch, Team Handball, Gunslingers and the randomly generated endless Infinni Runner for maximum chaotic chumily fun times. And finally a full feature level editor with Steam Workshop support and 60+ object types allows you to design, save and share your weird creations with chums for immense joy.

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Note the multiplayer game modes are local only, not online.