In your games you should prevent the character from running outside of the screen if there is nothing there. For example if I run at the room with the dragon to the right then I'm lost and can't come back and I don't die. So put an invisible barrier or a real barrier there.
I would make it like that you can jump if you fall from the platform. Like you can jump once while you are in the air. This would make the game flow easier because I got frustrated how many times I dropped from the platform because I hit the jump button 1 second to late. I finished all 3 levels then it started again from the beginning.
And I would add that you either use the arrow keys or AWSD to control the player. You have a typo "My thirst game". I think you mean "My third game".
I would also try to add a little bit more texture to the spaceship because it looks not as detailed as the other assets. Overall nice game ;-)
