This is a good first attempt. Don't feel sad you couldn't make it bigger, my first one was about the same length, and it took me 7 days. There are two things though that could have elevated the experience a bit in not much time -
1. Sound effects. Just some free sound effects from the internet make playing feel good.
2. Some more color. Most of it is just grey or black which makes it look dull. Just a ColorRect for a background and a different color for the platforms would have made it visually better.
Try to implement these in your next attempts, and good job!