28 This article gives more handy tips for designing a platformer. There are tips for movement on ladders and veins, jumping, ledges and platforms, the camera, interface, and other ways to make a fun game.
user interface
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24 In this article, the Dave Russell introduces the basic concepts of diegesis theory in video game interface design.
Video game user interface design: Diegesis theory
42 This article gives handy tips for designing and building a platformer. There are tips for designing the interface, handling jumping and collision boundaries of goodies and baddies, implementing AI, and other ways to make a fun game.