It's really neat to see an entry made by a young programmer! They should be very pleased with themselves for submitting. As I usually do, I like to provide feedback and suggestions for future games or work on the same project.
- As a player, having each character move in the same direction felt counter-intuitive. I think it would feel more natural if the left player can only move left and the right player only move right.
- In the future, think about adding sound and music. There's free assets here on itch and sites like opengameart. Not only will this keep the player's interest, but also provide the player feedback when something happens. If I get hit, I want some kind of feedback that lets me instinctively know I got hit and make me feel a sense of danger.
- I would also include a quit game button that closes the program, especially when its a fullscreen game.
Overall, they should be excited that they were able to submit to a game jam, and be encouraged to keep learning and making new things!