So first you need do determine what the win conditions is (points earned, time passed, whatever you want)
maybe add 1 to variable when the player triggers an on collision with the tests. and for each level you set this number. so when "tests collided = tests needed for level" a variable must be changed. (set WIN to 1)
when the variable has been changed, then you trigger the Win (and wathever you want to happen then)
at the start of each new level, WIN must be set back to 0.