If you have a Japan region Nintendo 3DS you can try Monster Hunter 3G right now. Capcom put a 1354 block demo of the game on Nintendo’s eShop. It’s free, but has a 30 play limit and each gameplay session ends after 20 minutes.
The Monster Hunter 3G demo is in a new demo section on the eShop. This folder also has demos for Puyo Puyo!! 20th Anniversary, Cooking Mama 4, Shin Chan: Universe de Achoo!, Nicola Editor: Stylish Model Audition 2, The 3D Illustrated Encyclopedia of Flora and Fauna, and Dead or Alive Dimensions.
Just for comparison sake, I also downloaded the Puyo Puyo 20th Anniversary demo, which also has a 30 play limit. It’s also one-tenth the size of Monster Hunter 3G clocking in at 131 blocks.