I think I made some pretty good progress so far. The player's sprite, title screen and background are definitely not the finished versions yet, but I'm slowly getting there. Also, at the moment I'm not worried about the display of the collectibles in the upper left corner, because I haven't finished the sprite yet and I don't think it would make sense to worry about the spacing too much at this point.
I couldn't solve the issues I had with the second and third text-boxes text animation, but I will get back to it on another day.
Things I want to fix ASAP: When pressing space to start the game, the player immediately jumps. If I can't find a solution, I will simply use another key to start the game.
Also I've designed three levels I really like today.