Thanks! I meant to add the shadow to all enemies but I didn't manage my time well. I will add that in future though.
For the timing of the enemies I had a spawner script. I used a variable string that would be for each stage, 0, 1, 2, 3 and 4. The process function is checking what state that variable is in and how many enemies have spawned, if it is in 0 and there hasn't been 5 enemy spawned yet, it runs the spawner for the first enemy type until there are 5 and the stage variable then changes to "0 wait" stops spawning.
Then the script is looking to see how many enemies are left, which is recorded in a Global script. When each enemy dies they minus this number. The spawner script is looking for this to change to 0, then it sets the stage to "1" and so on and so on.
The last stage, 4, then sets the last label for game complete and stops spawning.
Also each stage has a spawnTimer and waitTimer so that enemies don't spawn straight after eachother cos I found I'd just shoot them all accidently before they were on screen.