Day 20: Sound effects are an essential part of the experience
A game experience can be totally different depending on your sound department, so look out for the best possible sound effects for your project. This element can add a strong impact to certain scenes, or on the contrary, remove all force from your gameplay. Not only that, but you can also offer feedback to the player based on them: you can assign a sound for life recovery and the user will eventually be able to associate the sound with a certain action in your game.
The best horror video games are great examples of this point, as they are capable of generating endless emotions in the player with just one environment using good sound effects; you can play Silent Hill 1 today and immerse yourself in the bleak atmosphere of the game.