A number of teachers I work with often program a version of the ZX Spectrum classic, Frogger – http://www.worldofspectrum.org/infoseekid.cgi?id=0001887 within Scratch.
A basic version can be found here – http://scratch.mit.edu/projects/34385172/ If you fancy a challenge, why not improve the game? You might want to:
• Include sound effects when the character moves / hits the enemies (Hint: look in Sound)
• Change the Sprite to something different if it touches a butterfly (Hint: you’ll need to add a new Costume)
• Get the butterflies to change direction (Hint: use a turn block)
• Make the frog bounce across the stage if he touches the side (Hint: look in Motion)
• Add objects, such as food, for the character to collect (Hint: add some extra Sprites and Hide them when touched)
• Have different enemies, such as dogs or dinosaurs, on each level (Hint: only show certain sprites when a certain backdrop is selected)
• Include a score or a timer (Hint: store the values using a variable)
• Include additional levels (Hint: display a new background when the frog reaches the top of the screen)
Let me know if you enhance the game and I’ll share it online!