This is the third in a series of videos on Inform 7. It covers changing the status line, using Basic Screen Effects, and simple scenes.
Part 1: https://www.youtube.com/watch?v=oTm0bWagG_M
Part 2: https://www.youtube.com/watch?v=_DCBM1qZt-g
Blog Post: http://videlais.com/2013/03/07/learning-inform-7-part-3/
(For all code using Basic Screen Effects, make sure "Z-Code Version 8" is selected under the Settings tab.)