🦀 Crabs 🦀

A simple terminal game written in Rust.

• [CURRENT STATUS]: Alpha testing

This is a pretty minimal game in which you have to guide a consortium of crabs to safety. Gameplay is heavily inspired by Jagex's Flea Circus and DMA Design's Lemmings. I wrote this as a prototype for a full graphical version, which maybe I'll write one day using Amethyst. I have probably missed some edge cases in the game -- if it crashes whilst you're playing, post an issue (or, better yet, submit a pull request with a fix 😎).

Table of contents

1. Installation
2. Usage
3. Customisation
4. To Do
5. License

Installation

Requires an installation of Rust. Recommended build profile is release:

$ curl https://sh.rustup.rs -sSf | sh                  # install Rust
$ git clone https://github.com/lewis-weinberger/crabs  # clone repository
$ cd crabs                                             # cd into source directory
$ cargo run --release                                  # compile and run

[TODO]The latest version can also be installed directly from crates.io:

$ cargo install crabs                                  # download from crates.io 
$ crabs                                                # play

By default this downloads and builds the crabs crate, installing the binary in $HOME/.cargo/bin/. Otherwise you can download pre-compiled binaries from the Releases section.

Usage

The following (low-quality) GIF shows some gameplay:

A short explanation of the game can be found by passing the --help switch:

$ crabs --help

crabs --help
------------
Guide the crabs to safety:
	. crab
	X safety
Use the arrow keys to move the cursor:
	+ cursor
Insert scenery by typing the appropriate key:
	# block
	/ forward ramp
	\ backward ramp
	@ trampoline
Each level, type r to restart and q to quit.	

Use a custom map saved in RON format:
	$ crabs custom_level.ron
To adjust the crab speed:
        $ crabs --tick-time N
where larger N makes the crabs slower! Default is 100ms

Note that you can change the speed of the crabs using the --tick switch. This switch allows the user to specify the tick rate of the game (larger tick-time will slow down the crabs).

Customisation

There are a number of default levels built into the game, but it is also possible to play your own! In order to do this you'll need to create a map and add some crabs. The provided make-map program can be used to create a map in the appropriate format (a RON file). It uses the same user-interface as the game.

$ make-map                  # will prompt for filename, e.g. my_custom_level.ron
$ crabs my_custom_level.ron

Alternatively you can manually write a level file as follows: (i) the map can be loaded from a string which contains a rectangular block of text; (ii) the crabs need to have positions and velocities* specified. The layout of the RON file should be:

// my_custom_level.ron
// The below corresponds to a single crab (with ID 1)
// with position [y, x] = [2, 3] and velocity [vy, vx] = [1, -1]
(
    x: { 1: 2 },
    y: { 1: 3 },
    vx: { 1: -1 },
    vy: { 1: 1 },
    layout: "   \n   \n###",
)

An example level is provided in the examples directory.

*Note that the y-coordinate starts at 0 at the top of the terminal, so positive y-velocity corresponds to a downward velocity on the terminal!

To Do

1. Full graphical version?
2. WASM?

As this was intended to be a prototype, I don't have plans to add more features to this version, although it could definitely be expanded to include:

1. More scenery types, such as something that kills the crabs.
2. More/better levels.
3. More customisation, including different colours and characters used for display.

Contributions are welcome! Please submit an issue or pull request.

License

MIT License