3DS is technically impossible at this time. DS is technically possible, just requires a decent hack.
Then again, you're facing technical hurdles.
1. The 3DS has 3D. You can't replicate that on a phone right now.
2. Two screens. If you're on a 1320/1520, that's fine, but something else? Whoa there.
3. The 3DS is roughly as powerful as the cheaper 1st Gen WP8 devices. Ouch.
4. No physical controls. You want them? That's a lot of cash you have to cough up.
Besides, don't pirate. Support the dev whenever possible. If you don't want to, that's your loss.