...and other WM behaviour must be improved:

Some fullscreen apps grab most of keyboard shortcuts under their control. Especially 3D games, Sauerbraten for example. So it is impossible to use Alt+Tab with them.
It is also not good if app uses alt+tab in own purposes, but WM overrides it. Or there is high probability of accidental key press.
There should be some way to minimize such apps. Override control over alt+tab, or/and make another shortcut, that would be accessible from anywhere.

There are also situations when popups brake normal work of fullscreen app. Especially when using compiz.

So summing all:
- WM must have *switchable* ability to override alt+tab so it will work everywhere.
- it must have *customizable* alternative hotkeys that would work like alt+tab everywhere.
- it must have ability to turn off/on (and may be override too) other desktop hotkeys in fullscreen (may be customized for different hotkeys)
- it must not interfere in work of fullscreen app if user does not want it. When in fullscreen, new windows must be created minimized, and notify bubbles must be just drawn over fullscreen. No forced minimization because of popups!
- minimization, or popups must not break the app.
- if fullscreen app's resolution is similar or greater than desktop's, it must be minimized when pressing alt+tab (or custom replacement). If resolution is smaller, it *can* be shown in own window (switchable).
- it must have ability to lock/unlock mouse focus when in some windowed app that needs to grab mouse. Do it by some hotkey, like ctrl+F10 in Dosbox. (this addition based on idea #4642)

This is a game proposal that could be included in Edubuntu, it teaches kids about velocity, angles, gravity, physics, ballistics, external factors, mathematical calculation and estimation, etc in a fun, easy and entertaining way.

You can play versus the computer or against another player.
You both have a cannon each, your goal is to fire a cannon ball that hits the enemy cannon which destroys it, then you win.

To hit the target you have to decide the angle of the cannon and the velocity of the cannon ball. You must use the right angle and velocity to hit the target, else you will miss.

This teaches kids physics by ballistic trajectory of a projectile with variables such as velocity, angle and estimation of where the cannon ball will hit.

You may also need to take into account external factors and put into consideration stuff such as terrain and wind and compensate for this.

Mockup - illustrative image

People like games, and while Linux has done very well with the card games, minesweeper and tetris type games, lets get some games that people can really get excited about.

How about starting or supporting one each of a
1)First Person Shooter (FPS)
2)Massively Multiplayer Online Role Playing Game (MMORPG)
3)Real Time Strategy Game (RTS)
4)Other popular game types that Linux lacks (Other people, submit your ideas)

I have seen these types of games on linux, and some of them have been pretty good, but not many people know about them. Start new or support existing game projects that work on most Linux platforms, and make them something to be excited about.

If we can have Linux games that people are excited about and like playing we will have less and less need for WINE and dual-boot machines. (although I personally appreciate the WINE developers, they work really hard).

Ubuntu should develop it's own open source game development libraries. This could push for a unified way to develop games on Linux platforms. Fast ANSI C libs that don't act as an engine, but rather as a easy way to gain access to the systems hardware from languages like python,c++,java... Why should Windows attract all the game developers. If a standardized library is developed for Linux it would certainly make anyone Question the need to use Directx.