Trust me. It's not you.
The mounds of snow can be dug up by putting the little shovel icon on them and pressing E - This will add snowballs to your total. You can throw snowballs at the packages to destroy them, most are 3 hits. Once you've cleared 3 you can restart and hold a lot more snowballs and stamina - then you can dig and drop (S key) snow to build height or dig down to the hidden boxes.
Thanks for trying it!