How do I make 2 objects in Inkscape to have the same Path-ID?

You can definitely do the group method and turn them green with css styling if you know how to do that. I have found that shapes within groups in JetPunk usually turn green as normal. Is there text AND shape in the group? Anyway, you can make anything any colour you want when guessed correctly. Put this in your style section:

.svg-holder .svg-correct {

fill: (put the #code for JetPunk’s correct colour here, I forget it);

}

Now, if it’s shapes AND text, you’ll need to let the site know to only apply this to the shapes (or your text being green on a green background will be unreadable). Anyway, if that’s the case, the code’s almost exactly the same. Give your shapes that you want to turn green an extra class. Say, or whatever. Then you can do:

.svg-holder .svg-correct.greenify {

fill: (put the #code for JetPunk’s correct colour here, I forget it);

}