Any digital game cannot be made without 2D art assets. There must be 2D assets in some form inside the game. So, as far as game component optimization is concerned, every 2D asset should also be optimized. Optimization of 2D assets means these three main things.
Each asset frame should only contain the effective pixels to be used in games. Unnecessary pixels increase the asset size and memory use during runtime.
Not all images require full data information for pixels. A significant amount of data might be stored in each pixel, depending on the image format. For example, full screen opaque images should never contain transparency data. Similarly, depending on the color set, images must be formatted in 8-bit, 16-bit, or 24-bit format.
Image optimization tools can be used to perform such optimizations.
