Froggy Castle 1 (released November 17, 2003) is a whimsical vertical shoot-’em-up arcade game developed by Snowstep Development . In this nostalgic title, players control Pit the Hamster

This is where Froggy Castle 1 shows its genius. The level is split into two mirrored halves. Pulling a block on the left side moves a corresponding block on the right side. You must coordinate both frogs (one is a clone) to stand on pressure plates simultaneously. It is a mind-bending introduction to cooperative puzzle logic, years before Portal 2 made it popular.