Play your game and answer those questions in order to decide what is good in your game and what remains to be improved. Share all your thoughts and remember that everyone is a beginner at creating a game. It's normal if the game is not perfect and if things could be better. It's time to learn and make the best games we can !
As a player, you had to control your character to jump, walk and fight enemies. It can be hard to go until the end of the level. But sometime it's hard because the player is a beginner at this game, and sometime it's because the controls are wrong.
When the player enter the game, very quickly he/she must know where the action takes place, who is the main character, what to do to win the game and why he/she should go until the end of the level.
The subject of the game is sustainable development. It means that the player must learn about this subject when he is playing. It also means that you know exactly what he learnt thanks to your game.
Every aspect of your game creates, all together, an atmosphere. This ambience is stronger if there is a global coherence. If the walking animation of the main character look funny but the music of the game sounds scary, it doesn't fit together and the atmosphere is ruined. If the drawing of the platforms is too different from the drawing of the enemies, it's also wrong.
Your game is not perfect and it's totally normal, it's just the first draft. Improvements will be made until you obtain the game you have in mind. So, tell me, what change should be made and what is good enough to stay the same ?