That's how I am looking at it, LMom: gaining speed. My kids also like knowing that they're competing in real time with kids from around the world. They discuss the countries their opponents are from, names of their schools, kids' names, etc while they're playing. They're also comparing fine motor techniques to increase their speed. Ha! (Good thing the math is easy. All that multitasking going on...)
My 9 y.o. has extreme time limit aversion, so this easy stuff with the touch of geography information and real-time competition to distract him from the timer is perfect. (He also likes the bar graph representation of each child's progress and speed.)
My 7 y.o. dd loves changing her avatar's clothes and hairstyles! Ha!
The kids' most recent topic of discussion is the number of minutes they need to play and when during the day they'll play them in order to accumulate a certain number of points and get their names on the "top students" list. Strategy!