Video game designers create core features of video games. This includes storylines, role-play mechanics, and character biographies. They devise missions, challenges, or puzzles that players encounter. Video game designers also guide and collaborate with production staff. They solicit feedback from staff and conduct regular design reviews. They balance and adjust gameplay experiences to ensure the critical and commercial success of the product. They also create and maintain design documentation. This includes mock-up screenshots, sample menu layouts, gameplay flowcharts, and other graphical devices.