LEVEL 1
The man's legs
The second building from the left
The sidewalk, close to the screen
One of the trees doesn't have a shadow
The c in "Differences is an o in the second picture
LEVEL 2
The rightmost building in the background is missing in one of the pictures
The orange and red buckets of paint
The yellow bucket of paint
The sidewalk is different
The man with the yellow shirt's flip-flops
LEVEL 3
The robot's sunglasses
The robot's pincers
The signs say different things
There is a tree missing in the back (left of the single tree in the foreground)
The sun is in a different place behind the top cloud (this can be hard to see on some monitors)
LEVEL 4
The third rule
The fifth rule ("dinners" and "diners")
The seventh rule
The eighth rule ("dreams" and "draems")
The last rule
LEVEL 5
The grass at the end of the bridge
The shadow under the bridge
The cattail directly under the number
The plank in the middle of the drawbridge
The extra rock on the bottom right
Who needs hacks…the stupid lag makes me go trough walls and immune to shoots…also causes delayed death and even this http://postimg.org/image/dlyt07h19/
 "i saw her too, with lasers"){kind=icon}
 "Plants Vs Zombies"){kind=icon}
 "Spectrum Runner"){kind=icon}
 "Bowmaster Prelude"){kind=icon}
 "Infectonator : World Dominator"){kind=icon}
 "Dude and Zombies"){kind=icon}
 "'Til Cows Tear Us Apart"){kind=icon}
 "5 Differences"){kind=icon}
 "No Time To Explain"){kind=icon}
 "Battalion Commander"){kind=icon}
 "Pandemic 2"){kind=icon}
 "The Last Stand: Union City"){kind=icon}
 "Mu Complex : Episode Two"){kind=icon}
 "The Last Door Ch.4 - Ancient Shadows"){kind=icon}
 "Elona Shooter"){kind=icon}
 "Realm of the Mad God"){kind=icon}
Press "m"!