It would have been an odd pick for a Mario song, but then again, the Roxette one wasn't much better, although I do like Roxette generally. Somebody on Nintendo Forums had made an unofficial video with the Queen song as the soundtrack a while back. It was... ok.
I think the biggest appeal of trophies is the surprise when you see something unexpected and really cool. Wishing for specific trophies to be included kind of defeats that purpose.
Ridley should be a familiar/assist you can summon. Although that also would make no sense, because Samus would not be summoning Ridley.
IDEA: Make a space pirate a playable character, and he can summon Ridley.
I never got to actually try this game out, but I saw someone at an airport play it. The developer seems like a nice kid. More power to him for doing what he thought was right.