My answer to the Getting Unstuck: Day 1 Challenge: Create a project that whenever two sprites collide, one of them says, "Excuse me!" and the other sprite says, "Certainly." Press the green flag.
I used the sensing blocks. And then used a variable to count the strikes, so on the third strike, I could make UFO1 explode. I think I would have liked to make the ufos movement random. Particular like this challenge because there are so many ways to solve the challenge. How are you going to make the sprite move? How are you going to signal the collision for the sprites to respond?