Diorgo Jonkers has been working in the computer game industry since 2001, mostly making mobile games. Companies include I-Imagine, Smallfry mobile and Luma Arcade. Currently he works part-time for Luma Arcade, primarily as a game designer and occasionally as a programmer. He also writes, edits and publishes comic books (http://www.gep-comic.com/).
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.