It looks awesome, but there are a couple of things you should fix:
The grenade doesn't really have a defined outline, so it looks like a green blob.
You should have two or three possible grenade-ground-hit sounds, and and one of them should play randomly every time the grenade hits the ground. Just to mix it up.
The grenade-ground-hit sound as I'm now calling it is a bit too loud. :S
Otherwise, great job.
Would you possibly consider teaching me codes or events?
Also this.