For level 12:
Stack all of the small cubes on the left side.
stack them so you leave about 1/3 of a gap on the base block.
then simply balance the large block on the right hand side base.
Easy done
(+) If this helps :)
If you are stuggling with the final boss on level 20, i Reccomend using the homing missles. I defeated him and only lost 50 armour.
You can pretty much hug the left side on the screen and he can not touch you, Whilst your homing missles destroy him. (+) if this helps! :)
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