Every once in a while you come across one of those games that you haven't really heard of, you buy it on impulse, and are immediately glad that you did. In a game industry that's rife with overhyped disappointments, there's something poetic about a little-known game turning out to be excellent. Ninja Smasher! exemplifies this perfectly; you wouldn't think much of it at first glance and it hasn't seemed to garner much attention, but this is one of the best indie action platformers we've seen on the eShop in quite some time.

The story of Ninja Smasher is simple. The monster overlord, King Tengu, has kidnapped the princess and you must save her. It's about as barebones as it gets, but it fits right in with the game's theme of emulating early NES games. Throughout your quest this is further reinforced through text that's been intentionally written as if it were poorly translated from Japanese. Lots of games try and fail to create the sense of being an early NES game, but something about the story and writing of Ninja Smasher pulls it off quite well.

Gameplay is punchy and exciting, coming off as something of a cross between Ninja Gaiden, The Legend of Zelda, and Metroid. The moment-to-moment action sees you utilizing a broad array of weapons and Jutsu magic to dispose of your foes, and it can be quite gripping. For example, jumping from enemy to enemy and clearing out a whole screen without touching the ground is immensely satisfying; the physics are just right and the controls are tight and responsive. Considering how fast-paced and dynamic some of the fights can get, it seems as though a combo meter of some kind perhaps would've made sense, but the action is rewarding enough as it is.

The world is laid out in your stereotypical Metroidvania style, packed to the brim with secrets, collectibles and dungeons. A helpful grid-based map on the top screen shows where you are at all times and slowly fills out as you explore more of the world on the bottom screen. You start out with a simple katana, but deeper exploration of the overworld and dungeons will see you acquiring new skills and abilities that 'unlock' other portions of the map. It all fits together quite well, and the rate at which you acquire new abilities is nicely paced.

Dungeons are laid out in a Zelda-style fashion, consisting of 2D strongholds that grant you a new ability and end in a boss fight that raises your health by one. Though these start out as fairly straightforward and simple affairs, each successive dungeon ups the ante and adds in more complicated puzzles, floor layouts, enemy placements, and more. These dungeons – particularly the later ones – are the highlight of the game, walking that fine line between being too hard and too easy. They're challenging even to a skilled gamer, but they never step into frustrating territory.

In terms of presentation there's nothing here that's particularly impressive, but it still has plenty of style. Environments are colourful and diverse, the spritework is simple and clean, and the animation is smooth. The soundtrack features a collection of decent oriental-themed music that usually fits the mood of the environment that you find yourself in, though it does tend to play the overworld track a bit much. This isn't a retro-style game that's trying to push the limits of what pixel art can do in motion, but it comes together in a way that's significantly more cohesive than what you'd expect.

As for replayability, Ninja Smasher holds up surprisingly well. The main campaign only takes a few hours to complete, but there are plenty of extra HP and SP pickups along the way that you may have missed. The world size is almost perfectly judged in that it isn't large enough that you can easily get lost, but it doesn't make you feel claustrophobic either. The presence of fast travel via certain doors helps cut down on tedium, too, so a subsequent playthrough doesn't feel like such a drag. Also, the game even includes a timer on the top screen, so speedruns are easier to track.