Here's a bit of (hopefully amusing) nonsense I wrote for the NaNoWriMo SF messageboard...
How to tell if you're writing science fiction.
1. Your story opens:-
a) in a small rural town
b) in a boardroom in the financial district of a major city
c) in a pseudo-medieval kingdom with a Saxon/Norse-sounding name
d) on one of the less fashionable planets of the Zarg Federation
e) on the inside of a ping-pong ball
2. A major complication will happen when:-
a) an old boyfriend/girlfriend contacts the protagonist on facebook
b) the pyramid investment scheme comes tumbling down
c) an evil magician gains possession of a powerful magic object
d) the protagonist gets infected with a lethal designer virus, leaving just 24 hours to track down the perpetrator and obtain an antidote
e) a scarecrow named Stephen decides to become the conductor of a symphony orchestra
3. Your principle love interest has:-
a) silk-soft hair and a peach-cream complexion
b) swarthy mediterranean skin and deep brown eyes
c) a strong jaw, rugged features and permanent day-old stubble
d) any of the following: a blue scaly complexion; an exoskeleton; compound eyes
e) arms and legs made of old jam jars
4. By the end of your novel, your protagonist will have:-
a) shaken off their jaundiced view of humanity
b) realised that family means more to them than a high-flying career
c) restored the rightful ruler to the throne of Thrangor
d) discovered an alien-tech superweapon/teleport/FTL device and exploited it to destroy a tyrannical regime - or - transformed into a cybernetic posthuman ninja assassin, teeming with lethal nanotechnology
e) discovered they can trim their toenails using just the power of their mind
5. By the end of your novel, the world will:-
a) carry on much as before
b) be a fairer place
c) be restored to balance and order
d) be changed for ever, for good or ill
e) have turned into a giant turnip in a bowler hat
If your most common answer was "d" then you're probably writing science fiction.
If your most common answer was "a", "b" or "c" then you're probably writing something else.
If your most common answer was "e" then I would suggest seeking professional help as soon as possible.