A readme needs creating to showcase the project and include information about used libraries.

It's difficult to use the cursor on the GUI when it is a large circle, the cursor should be changed when using the GUI

When a particle reaches the edge of the canvas, it should stop like a wall

Canvases should be able to be serialised, and then saved or loaded from disk.

Many functions are missing docstrings and adequate comments

An open source license should be chosen and applied to the project before it is made public

There should be an ability to pause the simulation and resume it

The current implementation does a very rough estimate of a circle and is inaccurate at smaller sizes, the algorithm should be reworked to make it more accurate while still being fast

Add a lava particle which burns through other particles (except water) and replaces them with lava too

Add the particle water, which should extend to fill any space that it is within

Add a fire particle that lets off embers / smoke and burns flammable objects

Investigate where parts of the project can be optimised

1. Reworking algorithms such as update and _place_particle
2. Compiling some code using libraries such as numba

The top row and left column of pixels on buttons are not being detected by a click.

Implement a GUI that allows you to at minimum:

1. Change pen size
2. Select from available particles

Placing particles currently overwrites any particles beneath, there should be an option to disable this behaviour

Add a text tooltip so that an explanation is shown when hovering over buttons

Sand currently floats on top of water when ideally it should sink to the bottom