Thank you taking the time to write such detailed feedback! You are totally right about it being unfair that the fire continues to spread whilst you read the instructions. I do plan to delay the fire for a couple of seconds, give you a chance to read! It does spread too fast I think. I need to work on the part that spreads the fire, I have an idea to slow the spread as you fight it to give you more of a chance if you hold your ground. More applicable on the later levels when the amount of fire allowed before a game over is higher.
The animation is a shader that is manipulating the vertexes of the sprite. With this project I wanted to test out some recent learning I have done with shader code so most of the effects are using shaders. I do intend to introduce controller support as making it a twin stick will probably feel better! A crosshair is a good idea though, gives clarity.
Changing the environment is definitely a good idea, I have considered it in my design but never quite got around to it in this prototype. I also wanted to play around with the fire more, have different types that spread in different ways. Could work with the terrain, for example a fire that launches fire and extra space and could do so over a river!
Thank you again for the detailed comment!