A decent little shmup! That's a very ambitious first game. The enemies are very well designed and make the shmup side of things engaging. I don't think I have seen the genre mixed with a garage and map before which made for a fresh experience. I reached the end and had a fun time.
If I had any suggestions, my main criticism would be that the game is over explained at the beginning since the game really isn't that complicated. Most players could probably understand what is going on, and for those that don't, I don't think reading so much without context will be fun for them. Linked to that criticism, I think more investment in UI clarity would have been a big improvement. However, I understand how hard UI is to design and implement, and considering that this is your first game and that you had many ideas to worry about, you did a great job.
Well done!