The learning curve is a bit high. You go from 1's and addition straight to prime numbers and multiplication problems ending in numbers in the hundreds. Other than that, good.
Oh yes, just like a bug in any of those great games that have tons of funding to beta test with is "inexcusable" eh? And just like how they never receive patches, eh? And yet, you know the funniest thing. People actually *pay* for those games. This the most you pay is in time, which is your choice.
Okay, I found what is causing the falling off screen bug. And also found why it was never noticed in testing. No one bothered jumping around much. For now, don't jump, eventually a fixed version will be put in. It's not like jumping was necessary.
 "Negative Zero"){kind=icon}
 "Viking Chronicles"){kind=icon}
 "Happy Turtle Slayer"){kind=icon}