This was my first project after learning Python. I read the book Python Crash Course: A Hands-On, Project-Based Introduction to Programming (Third Edition) by Eric Matthes, and this is one of the projects that is included in the book for you to try out. This project took me three days (around 8-10 hours of continuous work) to complete and get up to speed.
Alien Invasion was a lot of fun, and I have played it a lot more than I care to admit.
Have fun, and let me know what you think!