Phased is a 2 players coop-SHMUP in which you have to play in sync to be more efficient. It's one of the first projects we made in group at ENJMIN. The only constraints given were to create a SHMUP in groups of 9.
The main challenges were to manage working in a big team and with a lot of different field of expertise (Sound designers, 3D Artists, programmers, UX designers, managers, and game designers).
At first, playing in sync meant: playing close to eachother, and shooting at the same enemy. In a last iteration of the design, we implemented a feature that allowed the players to merge and average their input. It proved to be more in line with the initial intentions, rewarding players for having a good communication. But unfortunately it didn't get out of the prototyping phase because we had to move on other projects.