Update 0.4

New Things:

- Power Ups

Power Ups Spawn every 15 seconds on the map, touch them activate them for a limited time

- Shield Power Up

When activated, gives the Player a Shield that destroys Enemies on collision. Doesn't work on Falling Rocks

- Destruct Power Up

When activated, drops a wave from the sky that destroys Enemies and Falling Rocks on collision, sends a 2nd wave after 2 seconds