What is your video game about? When I ask you that question you might be thinking about the story of your game. However the real answer you should be telling me is what is the point of your game. That is because in order to make a quality game you must have good game cohesion and have gameplay reflect that. For example Sonic is not about a blue hedgehog trying to free animals in the forest. It’s about maintaining momentum throughout the level. That is why Green Hill Zone is iconic since it’s the best designed level that shows the player what the point of the game is.
In the Green Hill zone the player is encouraged to keep their momentum by taking the upper path on the level. This allows the player to fly by enemies and finish the level with relative speed. The player is also graded at the end of the level to further encourage players to keep their momentum in order to get a better score. This is important because when your levels reinforce the point of the game it creates game cohesion which makes better games overall.
When designing your own levels you must first ask yourself what is the point of your game. What do you want the player to accomplish and feel while playing your game? This will help you make more put together levels and help with the design process. For example if you wanted to create a 2d platformer based on speed. You would put platformers and perfects lengths to encourage player speed and you would not put any obstacles that would slow player movement. Overall game cohesion is important when designing levels and its important to know what your game is about. That way you can create a meaningful experience for your players.
Image used from here : https://www.deviantart.com/jeikeytor/art/WALLPAPER-Sonic-the-Hedgehog-Green-Hill-Zone-691171429