Awesome!
That was amazing! I love this little game, the different wicked combinations of things that you can do is simply brilliant!
Two fairly simple suggestions:
1) Add a 'freeze' button where you can still add objects but there are no effects, so if you place a grenade it won't count down until you unfreeze, if you hit the guy then the effect won't happen till you unfreeze and items that you place won't fall etc. This gives you time to place plenty of grenades before switching to gravity vortex >:-)
2) Have the guy accelerate and suffer 'damage' when falling, the gravity vortex was a bit disappointing when just picking him up and dropping him. Similarly when I nuked his ass with grenades and he flew off screen (I switched the ceiling off) it was very disappointing to watch him float down without suffering any pain.
Brilliant work!