RCA411  I find this game to be fun and addictive, though I like puzzle and block games. The graphics are not terrible, they have a retro-feel, but how much can you do with a block game? The best part of this game is that each level has multiple concepts. I am considering registering the game to see what the 'locked' concepts are all about.

Nice.  
(Version 2.6.5)

RCA411  I agree. And not only that, the license agreement expressly states in capitals letters that the program may contain defects, and the accuracy is not guaranteed. This wouldn't be so bad if you didn't have to pay for a non-transferrable license after 30 days.   
(Version 4.3.9)