Sfera - sliding puzzle in curved space

3D space may have some curvature. Sfera helps to realize that. Sfera is a sliding tile puzzle game (like the classic 15 puzzle). But its space is curved. So its board has no bounds and is closed in itself. Click to slide a tile. Drag to rotate. Mouse wheel to evert the space. Each puzzle level is initially solved. Just explore it at first: spin it, mess around, reset. Then choose a mission (it shuffles the tiles) and try to reach the initial state manually. Next level becomes available when 2 of...