Any American high school student who's owned a TI series calculator and endured hours of math classes has no doubt discovered Block Dude. The simple puzzle platformer was centered around escaping from rooms by moving around a limited number of blocks, and presented a wonderful escape from the dreariness of algebra. Evidently, the creators of Ninja Usagimaru - The Mysterious Karakuri Castle were fans of it, as this game is centered largely around the same concept.
The story opens with a simple and rather forgettable premise, but it does its job. The residents of Usagimaru's home village have been kidnapped by Mononoke demons, and it's up to the fluffy eared shinobi to save them. On his quest he's accompanied by the diminutive bunny god Toyoukebime, who will aid the hero with wisdom. It's as bizarre as it sounds and the characters obviously don't go through very much development, but the story is obviously not the focus here, and it at least manages to give the setting a somewhat unique flavour.
The meat and potatoes of this game is found in its gameplay, which is centered around the basic concept of freeing villagers from their bondage and safely escorting them to safety. Each stage contains a villager who is being held captive by an Oni Spirit, and you must figure out how to utilize tools in the environment to free them. This primarily is focused on jumping around and moving blocks, which can be thrown, tossed, and dragged in order to create paths through the stages. You also have various tools to help with this, such as a kite that allows you to ride on air currents or a kunai knife that can break cracked blocks. Overall, gameplay isn't very action focused, but instead requires careful planning of what to do and in what order so as not to get stuck.
Unfortunately, Ninja Usagimaru: The Mysterious Karakuri Castle is just a little too inconsistent and difficult for its own good. It seems that this game picks up immediately where its prequel left off in terms of difficulty, and it doesn't take too long for it to dial things up all the way to eleven. Though sustained thought is usually sufficient to finding a solution to a level, the nature of the level design makes this take much longer than it should. Even in the first world, some puzzles have some pretty convoluted solutions and it only gets worse as the game continues; the levels get longer and ever more complex. Eventually, it devolves into a repetitive slog of trial and error until you blindly stumble upon the solution. There's no 'aha!' moment to be had, and victory feels unearned.
It's not that the concept of a deliberately paced block puzzler is flawed, but here it feels more frustrating than it does challenging. The introduction of a movable checkpoint that you can return to at the tap of a button helps to somewhat alleviate the tedium, but it's a half-measure solution to a deeper problem. See, each world contains ten levels, and all of them must be cleared before you can move on to the next set of ten. Ordinarily this wouldn't be a problem, but with the high difficulty of many levels, this can lead to bottlenecks and gating of content. If you can't beat a level and you've beaten all the others in that world, you'll be stuck there until you can finally beat the level. The difficulty curve is all over the place as well; one level can be a walk in the park that only takes about forty seconds and it's followed immediately by one that takes thirty minutes to clear.
Pacing issues aside, it's quite a pleasing game from an audiovisual standpoint. The music is themed around oriental-type music, which provides a nice serene tone to levels. It can get pretty repetitive during long sessions, however, as the same track is reused in every stage of a particular world; you can only hear a new track by progressing to the next one. The art style is clearly inspired by eastern art, opting for a watercolour-esque look. It comes off as being somewhere between Okami and Final Fantasy, with its surreal backdrops and chibi characters. In motion, the spritework is quite colourful and detailed, though there is a lot of overlap between stages. You'll be seeing the same blocks, tiles and enemies a lot as you progress; each level is essentially a reorganization of the others.
Overall, Ninja Usagimaru: The Mysterious Karakuri Castle comes off as a very middling experience. When the difficulty isn't wildly ratcheted up, the puzzles can be quite fun to solve, and the presentation is quite charming. Unfortunately, you'll probably be spending a large portion of your time with this game on a handful of levels that present a disproportionately high difficulty that prevent you from playing the rest of the game. We'd give this game a recommendation, but only to those of you who are very patient in your approach to puzzle games.