29 it is. mongoose deception. $199 walmart
I haven't been into mountain biking much for the last... nearly 10 years. But I would look at a local bike store and be prepared to spend $300 (maybe a bit more... inflation and all). The difference between a toy store bike (what you get at Walmart) and even a low-end bike store bike is pretty significant. Like, the difference between a bike you hate riding and a bike you enjoy riding.
All I can find on that bike is that it has Shimano components - no name for the component group. Go to Shimano's website and look at the list of component groups:
http://bike.shimano.com/. Deore or Alivio is probably the best you can hope for on a cheap bike, but years ago they also had lower-end components that had no names, just part numbers beginning with TY-. They put those components on toy store bikes, and they suck. I assume they still do that. Look at the derailleurs and brakes, if you don't the name (aside from the Shimano brand) it's junk.
You could also check out
http://bikesdirect.com/. Ignore the names on the bikes, they're all fake - they just take inexpensive frames (which you're going to get regardless at your price range) and add components.
Smart move picking a hardtail though.
Rapid-fire > grip shift.
Saying that you'd hate a $200 is overstating it a bit, but it is a big jump up in quality if you go to the next price level.