Fill the first row on the decoding board. Pick monsters up from the dock-bar at the bottom or from any row above, they will be placed in empty cells.

You can activate cells by clicking on them (you'll see the green highlight) to change monsters in exact position.

You also can swipe left-right and up-down on every cell to switch monsters.

Filled the row?
Tap tick to confirm.

After each try you get SPECIAL HINTS
Use them to get your next try closer to the Puzzle!

The BLACK icon indicates how many monsters are in the correct position.
 

And WHITE shows amount of correct monsters placed in WRONG positions.

You don't know which monsters are correct!

Logic matters! Don't contradict with hints and you will win. In any case.

In settings you can enable duplicates in secret puzzle!