Purpose of "Requires a mouse" is unclear

Currently the "Finding your app" > "Hardware requirements" section has a "Requires a mouse" checkbox.

Checking this checkbox sets the ::input:mouse debtag on the package. This, in turn, causes Ubuntu Software Center to check whether a mouse is connected. If it is not, it displays a warning: "This software requires a mouse, but none are currently set up."

I get this warning when I look at IFX-Supreme, a photography application; Bastion, a role-playing game; and Picsaw, a jigsaw puzzle game. I have not bought IFX-Supreme or Bastion, and Picsaw crashes on startup (bug 1035201), but I would be surprised if any of them actually required a mouse. I expect they work just as well with a trackpad.

It may be that application publishers are treating "Requires a mouse" as "Requires a pointing device". It would not be useful for them to treat it that way, because approximately 100% of PCs have a pointing device, and many applications require one. If that was the meaning, when the debtag was absent it would be more likely that the publisher had just forgotten it than that it truly worked without one.

We are the first significant users of the ;:input:mouse debtag, so we get to decide what it means. I propose that it should mean "requires a mouse in particular, not a trackpad". This would make it useful for FPS games, for example, which are difficult to play with a trackpad; or programs for configuring a mouse itself, e.g. changing the effect of its extra buttons.

That would require these changes:
* change the "mouse" checkbox label in MyApps to "mouse (not suitable for trackpads)"
   (it may save time to fix bug 1015675 and/or bug 1103520 at the same time)
* check Bastion, and remove the ::input:mouse tag if necessary
* check IFX-Supreme, and remove the ::input:mouse tag if necessary
* check Picsaw, and remove the ::input:mouse tag if necessary.