The eponymous angel, Pit, former leader of the personal guard of Palutena, the Goddess of Light and ruler of Angel Land, was freed from a dungeon in the Underworld by the aforementioned Goddess, using the last of her strength, so he could travel to palace in the Sky to save her from the evil clutches of Medusa, the Goddess of Darkness who ruled Angel Land along with Palutena. During his travels, Pit will have to recapture the three Sacred Treasures of Light, essential for him to stand a chance in his final battle against Medusa.
The game doesn't make a big deal of telling you the story behind adventure, rather focusing on the action, so like many other games of its time, Kid Icarus rather requires that you check its instruction book for details about the plot, or rather the digital form of it in the case of this 3D Classics edition. Pit must use his bow and arrows to defeat enemies in his path as he progresses. Defeating enemies increase the player's score. Those points also act a Pit's experience. Indeed, beating a stage with the total score exceeding a certain amount increases Pit's health bar, making the journey ahead that slight bit less difficult. Defeating as many enemies as possible consequentially becomes a necessity if you hope to stand a chance against the swarms of Medusa's evil forces. Enemies also leave behind hearts, or pieces thereof, which act as a currency in the game for buying items.
Action is set in 2D side-scrolling levels, where Pit must typically go from start to finish while defeating foes along the way. The first and third regions, the Underworld and Sky World, have stages that scroll vertically (where Pit will reappear on the left of the screen if he exits it from the right and vice versa), while the second region scrolls horizontally.
Each of those three regions ends with a dungeon stage without any scrolling but rather divided in rooms, à la Zelda, although viewed from the side instead of a bird's eye viewpoint. Those dungeons hold a boss and one of the aforementioned three sacred treasures. The scrolling stages don't require any kind of exploration, except for the occasional door leading to a special chamber. Those can be of different kinds. There are the Treasure Chambers where Pit can open up jars by shooting them, those either holding a precious item or a small creature called God of Poverty, which prevents you from catching anything. If all jars are opened without the God of Poverty showing up, the last jar will contain a very good item. Other chambers are the Sacred Training ones, where Pit can undertake the challenge of surviving against endless swarms of enemies for a certain amount of time. Should he succeed, he will be awarded with a power item to choose out of three that increase his fighting abilities, like extending the reach of his arrows or turning them into flaming arrows, among others. There are still the holy springs, for replenishing Pit's health, and the enemies’ lairs where Pit will be faced with a set number of foes to defeat, helping him increase his wealth.
More important still are the Sacred Chambers, where an old man may appear depending on a hidden stat commonly referred to among fans as Skill. Should you meet the requirements, Pit will be given a powerful arrow that will increase his strength, making all of his attacks more destructive. Skill seems to pretty much depend on the player's own skill and is influenced by things like the overall accuracy of your shots, the amount of enemies defeated, and so on. Last, but not least, are the item shops and black market. At item shops Pit can spend his hearts on items that will help him on his quest. It is even possible to haggle with the merchant to try and have him lower his prices.
Actually, it is more like ‘threaten to beat the merchant up’ rather than haggling, since the outcome of haggling depends on Pit's strength stat. If Pit's stat is at least superior by one to the first digit of the stage you are in, the merchant will lower his prices and say “I guess I can't win,” which leaves little doubt as to how Pit haggles. The disappointing part is that in the original Famicom Disk System version of the game released in Japan, to haggle, the player had to speak into the microphone built into the second controller of the Famicom. This was replaced on the NES cartridge versions released outside Japan by a button combination to press on the second controller, since Western controllers lacked any microphone. With all 3DS systems having a built-in microphone, though, one would have hoped that Western gamers would be treated to the unique idea, but this is unfortunately not the case as 3D Classics: Kid Icarus requires the player to hold down the A button and press Select to barter. Black market shops sell much more expensive but rarer items and don't let you negotiate prices whatsoever.
The dungeons have players going around a very maze-like structure looking for the boss battle, which will award Pit with one of the three sacred treasures. To help you find your way, a map is concealed in one of the many rooms that make up every dungeon. Once the map is collected, Pit can buy a torch at any shop within the dungeon so that his location is highlighted on the map, and the pencil will mark in green every room Pit has visited since he got said item. Therefore, finding both the map and shops is a key in exploring the dungeons. Inhabiting the dungeons are the Eggplant Wizards, which inflict the Eggplant Curse on Pit, making him unable to use his bow or any other means of attack. One or more hospitals are scattered throughout the dungeons where the Eggplant Curse can be lifted, sometimes requiring you to backtrack through the maze.
Below its apparent action-platform mechanics, 3D Classics: Kid Icarus is a very RPG-like game. You can tell from its dungeons and the fact that it uses a stat-raising system allowing Pit to be trained from a weakling to a powerful warrior by the end of the game, which is definitely required by the increasing difficulty of the various stages. The whole adventure is supported by an epic soundtrack composed by Hirokazu “Hip” Tanaka, famous for composing many of the oldest Nintendo game soundtracks. This 3D Classics edition draws more features from its Famicom Disk system version of Kid Icarus than its NES counterpart, using the same kind of save slot select screen instead of the “Sacred Words” password system, which is for the better. This can also be heard in the sound department, with some of the sound effects and music tracks clearly using the additional sound channel that the Famicom Disk System supported. Graphics look outdated now, of course, but still look nice enough. The meat of this re-edition is obviously ultimately the 3D effect, which works incredibly well. The black and empty backgrounds of the original are now replaced with detailed and more colourful backgrounds. Some of the details of the scenery are now placed further into the background when the 3D effect is turned on and those new backgrounds appear to be in the far distance behind the scene where the actual game happens. This truly gives the impression of the action truly taking place in a fantasy world that feels like it is really there, inside the screen, and gives a whole new dimension to the already epic original adventure.