To get to 1650, I needed 100s on levels 13 and 19, and 51 on level 20. I also managed to get 100 on level 2 with the "2-pixel thin slice and wait" on the top two boxes, but didn't need it for the badge.
I think the extra orb is to make sure you don't end up with a locked planet that contains a puzzle piece that's critical for one of your unlocked planets.
Very addictive, but once I saw level 81 (and saw that levels go up to at least 120) I'm willing to take a break. A bunch of green letters (they're additive) make longer words like governmental and fundamentalism much more valuable.
To get 3M feet without much skill: with tank and golden gun, load up on money until you can buy 60 nukes. Launch, then keep dropping nukes until you start to slow down (drift away from right edge). Then shoot to reboost, then keep dropping nukes again. 6 nukes + 1 golden bullet should get you 300K feet each time.
 "Pheus and Mor"){kind=icon}
 "3 Slices 2"){kind=icon}
 "The Book of Living Magic"){kind=icon}
 "Dude and Zombies"){kind=icon}
 "The Dreamerz"){kind=icon}
 "Lateral - The Word Association Game"){kind=icon}
 "Clockwords: Prelude"){kind=icon}
 "Take Something Literally"){kind=icon}
 "Toss the Turtle"){kind=icon}
 "My Pet Protector"){kind=icon}