Editing Snowball game code

Hi,

I'm new to Articulate Storyline and feel as though I've already bitten off more than I can chew.

I'm trying to edit this free template for the Snowball game so that the snow men falling from the top of the screen are multiple, random images i.e. you're able to throw snowballs at either a snowman, a santa or a candy cane for more variety.

Any help with coding this challenge would be greatly appreciated! Thank you!