Oh no, I'm adding Power Ups

Just when you thought the game was near ready, I decided to have a go with adding Power Ups, maybe even the kind of gems you can get with in-app purchases.

So far I only have three in-game buttons with ammo counts on them, and when they're empty, they slide away.

At the moment they don't do anything other than count down and slide away. But here's what I want to do with them:

- Top one should buy you some time to finish your level. Maybe 10 to 20 seconds.

- Middle one hits all enemies on screen with a blast. I guess that will be for UFOs only. Maybe it switches off blackholes, comets, sunflares for a while too.

- The one at the bottom turns on protection against lasers and collisions for a little while.