This wiki has been moved to https://github.com/SuperTux/wiki into the mediawiki branch.
Below you can find a list of ideas that have already been discussed and rejected, reasons for rejections should be included where available:
We won't include Beastie or any other FOSS mascot. SuperTux is meant as a good jump'n run, not as a showcase of walking FOSS logos. The use of Tux is because he makes a good starting point, one that other people can agree on, to create a world around him and less because he is the Linux mascot.
No useless items/actions/enemies
Any enemy, action or item added to the game should serve a specific purpose, thus allow something not doable by other items, enemies or actions. Different looking actions that serve the same purpose are most of the time just confusing and add unnecessary bloat to the game. There is of course a little need to have a variety of enemies, but even with them variety in behaviour is much more important then variety in look. Different looking enemies might make pretty screenshots, but different behaviour makes a better game.
No Magic System
There was a discussion on the mailing list shortly after the release of milestone 1 about introducing some kind of magic system that all of Tux' abilities are based on. Although details were never worked out, the general idea was to replace all powerups and some level objects by "spells" Tux could learn and cast using mana energy that needed to be refilled by collecting specific items. The idea was rejected because it would make the gameplay go in a completely different direction, and properly implementing and adjusting it could theoretically be a whole milestone in itself.