+r5k1/1R5p/3N4/4pP2/1p4P1/2p5/1rP1PKP1/8 w - - 0 1
+
Simultaneous games: view Game + Simultaneous, using component (One)Game
Storage: just key ID => IDs of actual games (in indexedDB)
In Hall challenge: acceptation on sender side (who launch the game when ready --> left click [which just delete if nobody registered, with confirm box])