Very clever! Really gives people a sense of ownership and agency in playing this small game. Evokes a nostalgia of the early 2000s for me. My critical comments are below.
Some improved usability and UI clarity would go a long way here for the player. It is unclear what is and what isn't interactable. I was not sure how the pens at the bottom worked at first, and didn't know that I needed to draw a sprite for the player too (although I know you gave some instruction outside of the game). I think that this is a wonderful idea for fitting the theme of "game development" from an artist's point of view. But for your next game, make sure that you spend a good amount of time on usability! It gets in the way of experiencing how fun of a little game this is.
For example, you could have had the player start the game by "flipping through" a few "pages" (the tutorial) before getting to the actual game. The first page could say something like "draw a picture of yourself." Then you draw on that page and click to turn to the next page when you are finished. The second page could say "draw your favorite weapon"... Then the next, "draw your worst enemy, your first home" etc. Your UI would be less cluttered (i.e. when you are in the "drawing mode", you literally just have things on screen for drawing, and not any other buttons). It would also give people a sense of what the game is trying to evoke here, that game development can be a very personal process! Once they get to the main menu page, you can allow people to go back and change their drawings or proceed to the meat of your game using their drawings from their own experiences.
Overall, great work on the idea and great execution! Best of luck.