Natto-Cat, which was formerly known as 'Rockhunt', is a unique Boulderdash game with a merry, light-hearted atmosphere. The creator's purpose was on one hand creating a game which stays close to the original Boulder Dash and which on the other hand gives another, original twist to the original game concept and leads an own path in an original, alternative way.

The main character of this funny freeware game is agent RB51 who is half a cat of the Russian Blue breed and half a robot. This sturdy hero's task is to find the required amount of cat snacks, wading through 'natto', which means 'fermented beans' and which is a Japanese regular food. (You pronounce the 'a' in 'natto' like an 'o' as in 'lot'.) Once he has collected all this food, the exit elevator can be elevated to leave the level.

On his food hunt agent RB51 will come across many dangers, such as falling dried plums and walking, explosive bowls with custard and expanding grean peas, which can block your path if you are not quick enough! Even for the cat snacks he must watch out, as they are deadly when they hit his head!

This game is certainly a recommendation if you like to play a Boulderdash clone which is funny and entertaining. The sounds and title music make it even more comic. With the game there come 25 levels and six intermissions (levels between, to have a rest), which can be played at three levels. This makes a total of 75 levels of fun! Besides, it is possible to load original Boulder Dash games (levelsets), which means that there are tons of new levels waiting for you! And a level editor is included, so you can even create your own levels!

The keys in Natto-Cat are simple: just use to arrow keys to move RB51 and the [Control] key combined with an arrow key to grab or push an object beside you. The game can also be played with a Joystick. If you do so, use the Fire button instead of the [Control] key. [Esc] will make RB51 die.

In order to play the game in windowed mode, turn off, decrease or increase the amount of blood and custard splatter effects, change the game speed, CPU use and to change some other settings, you can edit the included prefs.txt file. To speed up the game (which is relevant if you use a slow computer), you can lower the time_delay value, which will make Natto-Cat use more CPU resources.

Natto-Cat has been created by Aaron Maupin, with the help of Ayaka Okada, Matt Rea, Sachie Kanda, Todd Maupin, Patrick Mullen and Brian Fisher. It has been programmed in Python and it uses Pygame as a wrapper for SDL. The game runs in Windows and a 1 GHz machine with generic on-board graphics acceleration is probably fast enough to play Natto-Cat at its intended speed.


Download Natto-Cat here: 

Natto-Cat The game itself


Click on the screenshots below to enlarge them.

Screenshot 1 Screenshot 2 Screenshot 3


Natto-Cat supports three file formats: *.RHC (the native level format), *.D64 (Commodore 64 computer disk format which can contain levels created with the Boulder Dash Construction Kit (which were originally *.CAV or *.INT files)) and *.BD (Boulder Dash Common File Format). Levels created with the Boulder Dash Construction Kit and levels in Boulder Dash Common File Format (BDCFF) can both be downloaded from the Classic Boulder Dash page, because it is useless to provide them twice for download. Please note that of the *.D64 files hacked or non-standard levels are not supported and that of the *.BD files some files might not work either. The latter type of files doesn't always work because there are still some minor bugs in importing in procedurally-mapped levels (caves).

Below you can find level collection in the native Natto-Cat file format (*.RHC). If you have got new contributions, please your levels to Aaron Maupin (the author of the game) or to me (you can find my e-mail address in the navigation menu in the top-left corner of this page).

It might happen that you overwrite the existing Natto-Cat levels. Don't worry! Just download a new file here: default.rhc.

Levelset Name Number of Levels Author Description / Note
Unfortunately there have not been created any levels for Natto-Cat yet. Be the first to create a collection and send them to me to add here!


Here are a bunch of tips which can become useful when playing the game:
1. Falling cat snacks are just as heavy and dangerous as falling dried plums, so be careful when running to and fro at the bottom of a pile of cat snacks or you will be crushed by them!

2. Custard bowls always move clockwise along walls, whereas rabbits always circle walls counter-clockwise.

3. If expanding green peas fill a cave too much, they will change into plums. If they cannot expand any further, they will transform into cat snacks, just as green peas do.

4. You can push single dried plums when there is an empty space on the other side of it, but it sometimes takes a few tries before it will actually move. RB51 is not always that strong!

5. When cat snacks are falling past, you can easily grab them by using the [Control] key + an arrow key (or the Fire button and the right direction on the joystick if you are using that).

6. If you have coincidentally overwritten the standard levels in Natto-Cat in the level editor, just download a new default.rhc file to undo this mistake!


Below you can find links to other sites about Natto-Cat (although you can find everything on this page already).

If you know more about a certain game or if you have a new game, new levels, music or whatever, please send it to me and I will put it on this website! You can find my e-mailaddress in the menu to the left.