Welcome back, let's finish our game from last time.
1. Add logic to your Scratch program that lets Scratch move up and down with the up and down keys.
Make sure he hits the floor and ceiling. Don't let him be able to go beyond the screen.
2. Add the water balloons.
When you hit space, you want to be able to spawn in a water balloon where Scratchy is, and fire it straight rightwards. You'll probably need a 'go to' so that the ball can go to Scratchy's position first.