Simon Tatham's Portable Puzzle CollectionIntroductionThis page contains a collection of small computer programs which implement one-player puzzle games. Black Box [ java | js | manual ][ blackbox.exe ] Find the hidden balls in the box by bouncing laser beams off them. Loopy [ java | js | manual ][ loopy.exe ] Draw a single closed loop, given clues about number of adjacent edges. Undead [ java | js | manual ][ undead.exe ] Place ghosts, vampires and zombies so that the right numbers of them can be seen in mirrors. Some people have ported this puzzle collection to various mobile devices.