"Our goal was to make a power up system that allows people to get every single thing in the game without paying a cent." Um, no. Given how slow earning gets, and how many blops that would take, this statement is effectively false.
This does have a very nice Atari 2600 feel, but if this were REALLY retro, you'd die and lose all your lives if you bumped into the wall. Oh, and you'd only GET one life. AND you'd have to start over from the beginning level if you died, losing all your progress. Yeah, that's the way REAL men... er kids... played back in the day.
 "10 More Bullets"){kind=icon}
 "The Space Game: Missions"){kind=icon}
 "The Programmer RPG"){kind=icon}
 "Bit Battles"){kind=icon}
 "10"){kind=icon}
 "Champion"){kind=icon}
 "Stealth Assassin"){kind=icon}
 "The King's League"){kind=icon}
 "Bloons Super Monkey 2"){kind=icon}
 "Elona Shooter"){kind=icon}
 "Kongregolf"){kind=icon}
 "Pixvader"){kind=icon}
Woah! Interesting stuff - hadn't heard of Project Euler. I think *beastly* is a good estimate! Thanks PJ6211!