You are the square. Avoid the blue circles (enemies) and collect the yellow circles (coins). After you've collected all coins, move to the green area to complete the level. The first light green area is the starting point and the remaining ones are checkpoints. You can change the color of player. This is a modification of WHG on Scratch. All levels are possible
Enemies move at 10fps. Made 3 levels. Use turbo mode (shift+green flag) to make player movement faster (realistic). Only one coin sprite was used, using clones if necessary. Really cool. Warning: Coins will not be reset after death, so once you collect it, you won't lose it.