Nintendo eShop now has a Demos service. You can freely download their first demo, Resident Evil: Revelations, right now.
I tried the Resident Evil: Revelations demo just minutes ago. I have to admit the controls are very awkward, but the game is fun and scary. I enjoyed every bit of it, but I do not see myself buying the game. Granted, I may change my mind if I have extra money on me and I see it in a store.
The awkward controls may be fixed by investing in a new 3DS accessory called Circle Pad Pro, which adds a second joystick and two extra trigger buttons. Unfortunately, the accessory needs additional batteries and could weigh the system down significantly. If you want such a control scheme, the PlayStation Vita already has a second joystick, but the extra trigger buttons are a very nice touch. Overall, if you already have a 3DS and need an accessory to improve it, the Circle Pad Pro shows a lot of promise. (See the image on the right.) The price is only $20, so it is a reasonably cheap investment, anyway.