>>11848521
You can use twilight menu/patcher on 3ds to apply new filters, as well as widescreen hacks. If the game is 3d, it actually renders the extra screen width, it's not just stretched.
if you go through the trouble, the analog stick hacks are also very good.

Here's a comparison of a dsi xl(the largest screened way to play pixel perfect nds) vs new 3ds xl