"7dfps is a game development challenge, to make a first person game in seven days."

"Q: Can I...? A: Yes! "

So if for example I made a top-down 2d game from the perspective of someone in the air...that's fine? You can see how these things get a bit off-center if for example you are playing from "God's perspective"...well then an rts fits the criteria easily.  And what does the 7d mean? 

"7dfps"= Seventh December running first person 'game'...? my best guess atm

I think it's meant to be "7 days to make first person shooter" 

From the screenshots page, it seems a lot of people are submitting 2D and non-FPS games.  I guess it's up to the organisers to clarify what's allowed.

Anything is fine, it's not a competition so you can do whatever you feel like. The rules are pretty general on purpose! It started out more specific originally (but still the same rules!) and changed a bit to be less specific (fps -> fp) but either way, it never had such rigid goals.