A and D/left and right arrow keys to move, W/up to jump, and space to throw balls. Don't touch snowballs, moving ice blocks, or Frostre EX. Touch a ice block to kick it. Kick ice blocks at Frostre EX to deal damage. Frostre EX is extra icy. If you beat Frostre EX without taking damage, post it in the comments.
If you have any ways to differentiate Frostre EX's move-set from his normal counterpart's, let me know in the comments! Thanks to @griffpatch for the the Scratch Cat sprite.