Escape from Minecraft

You don't die from the arrow, just losing half your health, thankfully it doesn't cause you pain or anything. But you still need to get away from the skeleton, so you close your eyes and wish with all your half-a-heart to become something else. To your surprise, you somehow turn into a tree, and the same skeleton that shot you wanders around looking for you before eventually going away. You just learned you have shape-shifting powers!

Now that you've lost the first skeleton, you decide to start building something.