a lot of us use linux or osx, mind posting it as a .love?

well, there are probably going to be objects without userdata unless you're explicitly setting them yourself. you'll need to do something like: if fixture1:getUserData() and fixture1:getUserData().obj == "portal" then ... if fixture2 ... you could do something else to determine it's a tabl...

They're supposed to represent the same point in space, right? You may be overthinking the problem.
If you need to attach any arbitrary data to the fixture you can do so via fixture:setUserData(aTable)

I think what you want is a sensor.
http://www.love2d.org/wiki/Fixture:setSensor

the second argument should probably be mousex - playerx rather than playery

There are actually some pretty impressive C frameworks for writing nintendo ds games. It's not so much that it's impossible as it is that love depends on some pretty general purpose tech to display stuff to the screen because it's meant to be platform independent. On a DS you really want to use hard...

I do not believe there is currently a way to run love2d games on the nintendo ds.

probably version 0.99.1pre

Sounds like a nice in-between solution.

What triggers weapon upgrades? It was tough to pay attention once the big laser came in

Way awesome. I think I got carpal tunnel from hitting z/x so fast. How do you feel about autofire?