Go figure. My mother-in-law plays solitaire on a $1,000 PC hooked up to the Internet. Not exactly the smartest use of available resources. Or, is it? She spends hours engaged, interested, even excited, playing a game she enjoys. She exercises her brain, strategizing how to win. So, who’s to say what is right or smart? I related much more with her after downloading Fun Towers on my $600 Nexus One Android phone.

Fun Towers is a card game variant of solitaire. You’ve got three “towers” of face-down cards, each initially blocked by a single row of face-up cards. At the bottom of the screen, you’ve got a deck to draw from and one face-up card that drives the action. You must pull cards from the initial row and then the towers that are exactly one higher or one lower than the current face-up card, and place it on top of that card. The object is to clear all the cards from the table. And, oh yeah, there’s a time limit.

The game defines simple. Simple graphics, simple rules, simple options. You can change the look of the playing cards, adjust the shuffle algorithm, and toggle whether the phone vibrates when you touch an invalid card. That’s it. There’s no flashy celebration for beating a level and moving up, no change in gameplay of any kind.

Yet, despite the simplicity, Fun Towers is gripping. You can strategize your tower takedown approach, and there’s a real thrill from clearing the table, ’cause with the brief allotted time, it’s hard.

Does Fun Towers match up against the intensive-graphics Android games? Not in eye candy. But, in the “lost time” factor, when you look up at the clock and two hours have inexplicably vanished, Fun Towers hangs with most games out there.

If I rated only on engagement, Fun Towers would get 5 out of 5 bars. But, in respect for the hundreds of hours app developers spend on exciting graphics, I have to rate Fun Towers three out of five. If you like Solitaire, download it.