A big part of making a game interesting is making it immersive. There are many components of a game that work together that allow you to be stuck in the world that the video game is creating. One of my favorites of these is audio. Without audio, a game is silent, and doesn’t display or give the player the feeling that they are in this world, because the world isn’t mute to most people. Sound effects will provide the player feedback and information about what is being done in the game (player shooting, player walking, bird chirping, etc.). A sound track will also provide the developer’s interpretation of what theme the game has going for it, as well as immerse the player even further into the game. The sound track can put you in the spooky mood for horror games, or make you feel heroic and invincible with orchestral and powerful music. Ignoring sound in your game is a fatal move.
But getting a bunch of sound effects makes the game a larger size
Not necessarily. If you want a variety of sounds and unique feel to your sounds, all it takes is one or two different files with some programming in there. With the power of pitch bending during runtime, one sound effect can be infinite sound effects. Your player footstep sound just became more realistic, with having each step sound different than the last. Using a random number as an additive to the original pitch can make the sound lower higher, or slightly different each way to never get tired of that sound driving a hole into your brain. For more information on how to make your game feel more immersive, check out this video: https://www.youtube.com/watch?v=pmSAG51BybY