Kid Icarus first released on the Japanese NES in 1986. It re-released in 1987 in the West. In 2011, Nintendo released a promotion offer for those who register two 3DS games to get a download code to download Kid Icarus 3D for free. I was one of those people who got the game for free.
The game has undergone some changes. For example, there are now backgrounds in the levels and there is a scoring system on the game. The game's core gameplay still stays the same as the original, but it is still fun. I like this game a lot as it has a lot of challenging platforming gameplay as well as bosses and the visuals look great in this re-make. The only problem is that the dungeon levels take a very long time to navigate through. These levels are longer than the Zelda dungeons/temples!
Overall, I recommend this version of Kid Icarus over the original NES version as it is updated and it doesn't have any slowdown or flickering like the NES version.