Valve is generally supportive of mods (hell, a Portal 2 mod was just released a few days ago) but it seems like recreating Team Fortress 2 was pushing it... Really sad, honestly. I really hope Valve would just strike a deal with these devs and make it official rather than throw away the insane amount of effort they put into re-building TF2.
In this game, players must arrange characters and scenes to complete story objectives presented at each level. The challenge lies in figuring out the right combination to achieve the desired outcome. storyteller rewards players for their creative thinking and ability to solve narrative puzzles, offering endless ways to approach storytelling.