Professor Pip has shrunk the S.S. Millie to the size of a ribosome and squirted it into an animal cell. Meet everyone inside, collect every passport stamp, then go and bother the neighbours.
Bump into someone to get their stamp. Tap a stamp to reread their science.
On a phone: left stick to steer, buttons to rise, dive, honk and zoom. Drag anywhere else to look around.
Bump into anything with googly eyes to talk to it. The yellow beacon shows where your mission wants you. Mitochondria refill your ATP.
Every organelle met, every neighbour bothered, and the Golgi only mildly offended. Professor Pip will now re-embiggen the S.S. Millie, probably.