As a two players game, the challenge was to give to each player a real impact in the mechanic and not just make a second player a clone of the first one. To reach that objective, we built a mechanic around the « Duopulseu » device making main player movement depending of both player. One cannot go without the other. They need to communicante and synchronize to performe the « duopulsing » and master the skill. Also, each character has a unique ability allowing the résolution of puzzles and level design challenges.