If you've finished the first one and the demo of this one, you are basically buying 5 extra minutes of gameplay. The Puzzles are good, not too easy, not too "out there", visually the game is very unique and charming.
It costed me 1.59€ on a promotion so I can't really say they haven't earned every cent, specially if you want to thank them for Samorost 1. But seriously, unless you loved the first one, go play Machinarium instead, the puzzles are just as good and the game takes a lot longer to finish, the longevity of this game is revolting.