First of all let me say I am a big fan of both Adventure Time and The Legend of Zelda Series and when I saw this game I was rather excited as this seemed like the ideal formula for an adventure time game and if a sequel is released with the issues in this game addressed it could be a real hit.

I also wish to mention that due to constant issues with crashes (which will be expanded upon) I was unable to complete the entire game but from the various lets plays I've seen since the game itself is rather short (4 dungeons from which I completed 2) but with a lot of back tracking.
 
Now in this review I'll go over the following areas in depth, Story/Theme, Controls/Game Mechanics, Graphics/Sound though it should be noted there may be overlap at times.

Story/Theme

Adventure Time: The Secret of The Nameless Kingdom strongest point is its loyalty to it source material, the games plot could easily be made into a two or three part episode and be well received and its newly introduced characters all have the charm and strangeness one would expect from Adventure Time.

Nearly all the monsters can be recognised from the show however there is no real reasoning or theme why they are in a location and are often recoloured and reused elsewhere throughout the game with only with more hit points to create an additional challenge, there is also no shortage of cameos from major and minor characters, all of which are voiced and have perfectly written in character lines.
This been said there is not nearly enough character interaction between them with each only having a handful of lines. Another minor issue is that unless you are very familiar with the series many of these cameos will be unrecognisable and having a small character journal which unlocks a paragraph about each character you meet would of been a nice addition.

Outside of cutscenes Finn is the only one who speaks at least in the early periods of the game, these short lines are spoken each time Finn picks up an item or treasure with 4-5 lines of alternative dialogue for each. While these didn't bother me so much as I naturally phased them out I do know players who would be driven crazy by this over the first hour so this is just a warning for those who have little tolerance for such things.
This also highlights another issue which is the lack of banter or comments by character to the environments or bosses as you go through the game, this feels like a real wasted opportunity and unfortunately means there is little to distract from the lacklustre game play that is the core of the game.

While there are side quests in the game they are of "Find Item A give to Person A collect item from person A give to Person B" which is typical of top down adventures, the only trouble been the location of these characters are not marked on your map and are often in tedious/awkward to travel to locations.

Controls/Game Mechanics

As basic controls go the game is passable, if you have played any of the gameboy Legend of Zelda series you'll feel pretty much at home however in spite of this you'll find travelling and combat becomes a chore.

First of all Finn seems to move slightly too slow which combined with the large amount of travel, exploration and fetch quests in the game begins to grow frustrating, also there are numerous stairs and cave entrances/exits which you need to traverse and unless you are exactly in the centre of them you just walk against them rather than up/down/through them which often leaves you open to been struck if your just passing through an area trying to avoid combat.
This can be a further problem when moving up or down stairs as due to this been an animation you cannot attack or stop but this often lead to cheap hits from monsters gathered at the top or bottom, while there seems to be an invisible barrier in place to try and prevent this it doesn't work very well and actually causes issues with any block pushing puzzles that require you to push the block past a doorway.

These movement issues begin to also affect combat as well with many monsters been able to out pace you in general or with sudden bursts of speed resulting you get hit (as any monster touching you harms you) or miss a swing often as unlike Link Finn requires to stand still to attack with his sword which again slows down the gameplay and makes combat somewhat unsatisfactory.

The Grass sword is your  main weapon throughout the game as Finn and has seeming extremely short range, I say seemingly short range as the hit box for the blade is very difficult to judge but as a starting weapon it has reasonable power with some early monsters dying in a single blow.
However by the second dungeon many foes take up to 4-5 hits combined with a slightly too slow swing animation and the inability to move when attacking means you'll be getting much closer than I suspect you need to and as such take damage more often than you would normally.
The sword can not be swung diagonal so if your moving diagonally and need to attack you will swing in the direction closest to the angle you are moving which again can result in been struck by enemies approaching you diagonally.

Even hitting a monster can actually do more harm than good in most cases as it knocks away and with most monsters possessing range attacks and you'll often get hit just as your moving in to finish them off. The ideal way to avoid this is to obtain the boomerang stand in which like the Legend of Zelda series paralyses monsters briefly if you hit them (and can be thrown diagonal) and then go in swinging.

You also get a ranged attack yourself by the second dungeon but you again need to stand still when using it, its slow to fire, it does less damage than the sword, if you miss you have to wait until it strikes a wall or goes its full screen travel distance before you can fire again which means its only good as a utility item in most cases.

Your main defence other than hopefully moving out the way of the monsters far faster attacks is a shield which bluntly borders on useless, Like the sword it can only be used in the main four directions it is also extremely picky about positioning and will only block attacks that are central on Finn, a few pixels either way and you'll get hit. Its inconsistent about exactly which attacks it will block for example it will block a monster that is running at you with a blade knocking it back but if a monster just walks into you it won't stop them and when using it to push spiky objects you can suddenly slip past its perfect blocking spot and be damaged.

With these issues combined with the fact that monsters respawn the moment you re-enter an area you'll quickly start trying to avoid unnecessary combat unless you need money, this brings us to the next few points the shops and baggies..

Baggies are small plastic bags and essentially fill the role of glass jars from the Legend of Zelda but serve a wide range of functions, they are your potion bottle, your bomb bag, your monster catcher, by the second dungeon and I had already found eight items that can go in them, however they are as rare as hell and you'll often need a spare one to get through a dungeons puzzles so as a result all the different healing or buff items which you could collect (which are lost if you don't have a free bag btw) or buy (at absurdly high prices) will be ignored or you'll be forced to waste them as you need the space.
Those of you familiar with Legend of Zelda know that there are multiple different values of Zenny and Zenny chests littered everywhere, in Adventure Time: The Secret of the Nameless Kingdom you get coins (or Rubles in game) in values of 1 sparsely (3-6 a screen if lucky) on average and chests are rare often giving you trail mix or one of the other healing item components (which you also have to pay to create). To be fair the most expensive thing I have bought was 200 coins but the combination of low coins, little bag space and high prices means I rarely go near a shop.
One final issue with the Baggies is the inconstancy of how to put items them sometimes you will have to use Jake to grab an item other times you must equip the empty Baggie and use it, both these animations force you to stand still which is again frustrating when the item your trying to pick up moves around, while this doesn't have a massive game play effect it just feels that they shoehorned this in as a way to make Jakes grabbing hand have a use.

Now I must mention that to save the game you must do it manually and the only reminder to do so is when you are about to quit the game, this wouldn't be so bad in some respects but given how unstable the game is and how it can randomly at anytime crash to desktop it is damm right infuriating and I lost 2 hours of play twice. In this day and age there is no excuse not to have an auto save after a dungeon entered, side quest is finish or a boss defeated, its sheer laziness not to have this function and to be fair this underlying laziness and feeling of bare minimum effort is something that seems to plague all the Adventure Time games so far.

Graphics/Sound

You may have noticed that I've made references to the Legend of Zelda series through out this review this is partly due to the genre of the game and how highly it resembles Legend of Zelda: Link to the Past but also because the game itself is forcing a comparison between itself and Link to the Past in its very visuals throughout the game. Take these two screenshot as an example:

 

The environment and Finns actions all reference Link to the Past in design and many of the puzzles are similar, however I will give credit to Adventure Time: The Secret of the Nameless Kingdom's bosses as these do not follow the common "Use the item obtained in the dungeon to beat them" pattern and are honestly the most enjoyable aspect in the game.

However the issue with all these design similarities is you lose a lot of the uniqueness of the Adventure Time series and makes it ever so apparent you are playing a poor Legend of Zelda clone, if they had gone a little further perhaps making the first dungeon a room by room copy of Hyrule Castle with a twist before moving into there own unique design for the rest of the map that would of served the purpose so much better than the constant presence of Legend of Zelda references.
The game unfortunately looks rather ugly as well due to the contrast between the smooth backgrounds and the pixelated sprites of the characters within the game, again the cause of this is laziness by the developers as the sprites have been ripped without enhancement from Adventure Time: Explore the Dungeon Because I Don't Know.

As for the music there isn't much to say, its inoffensive and feels appropriate and upbeat most of the time but you won't be humming it and you'll forget it the moment you close the game.

Summary: Reasonable Zelda Clone that while has charm and is faithful to its source material suffers from poor communication and player feedback regarding objectives and puzzles, clunky controls, lack luster pickups/powerups and finally no autosave with a tendency to crash after cut scenes potentially losing hours of play time.

Thanks to various emulators and the Nintendo store there are far better games available at far cheaper prices.

6.5/10 Do not buy at full £30 price, purchase only with 80% off or more.

If you would like to see further reviews of this game and Adventure Time: Explore the Dungeon Because I Don't Know then I recommend reading the reviewing the following reviews over at the http://metro.co.uk

Adventure Time: The Secret of the Nameless Kingdom

Adventure Time: Explore the Dungeon Because I Don't Know