Sometimes run slow online, download for best performance. A sort of mini quest I made to try and figure out lighting techniques for colour. WASD moves the player (green dot). Collect the keys (coloured balls) to unlock the corresponding doors. Get the treasure at the end to win. You have very little light so you'll have to remember the path you took or you will get lost. I used two methods for making the light look how it does. The walls are a seperate sprite, black like the background. The light source, a simple gradient, will appear on the floors but not the walls because the wall is a layer above it. For colours I have the sprite change the "ghost" effect depending on distance and optimize it by having the sprite disappear entirely and become static when the player is a certain distance away. The ghost effect can cause a lot of slowdown so that optimization was extremely important. The only colour used here was the keys and doors but it can be used for moving sprites and anything that isn't too big.
