No missable achievements (plus 30 unknown)
Sign in with Steam or Xbox to track your progress, and:
Unlock Selene
Unlock Rao
Complete all the puzzles on a level with more than one
Complete Tau Ceti
Complete one level in Selene
Complete a puzzle on the alpha, beta, gamma... levels of the game
Exit through the yellow wormhole in Impossible Path
Unlock Altair
Unlock Cygnus X-1
Complete one level in Cygnus X-1
Complete all levels in Rao
Find all the combinations of The Safe
Unlock Rho Persei
Complete Quadrangular
Unlock Sirius
Complete all levels in Altair
Finish the game
Exit through the green wormhole in PAC
Complete all levels in Rho Persei
Complete all levels in Sirius
Complete all levels in Selene
Complete all puzzles on the alpha, beta, gamma... levels of the game
Complete, at least, one puzzle in each level
Complete all the puzzles in the game
Complete all levels in Cygnus X-1
Complete The Dark Side without moving the lights
Get all Space Pumpkpins (halloween special event)