@TheRealArse
SPOILER ALERT - Level 15.3:
1) Make a crevice in the top layer just to the left of the left-most rock.
2) Use wind to the right.
The three guys on the right will roll off with the wind. The guy on the top-left will fall down the crevice onto the guy on the bottom-left killing them both.
I find it disheartening for the total score (and level score) to use your most recent level scores rather than your best level scores. Yes, it keeps track of your quickest finish, but it doesn't use that time as your score unless it was your most recent attempt.