itch.io

Lol, damn, maybe it was a bit too hard.
It's a  columnar transposition cipher; it requires you to shift the letter columns and the most top row is the key.

Unscrambled it looks like this:

K  E  Y
H  A  P
P  Y  C

And the columns are then shifted according to the alphabetical order of the letters in the keyword (in this case KEY becomes EKY).
Here's the puzzle again:

E  K  Y
A  H  P
Y  P  C

And thus the answer is HAPPY(C). C is a null character added just to fill the column.