Thank you very much for your comment! That is precisely one of the reasons (along with the art) why I decided to stop the development. There isn't much reward for advancing to the next level. The enemies are a little more difficult, but visually there is no impact, and that is my mistake from the concept stage.
On the other hand, I'm going to fix the “Game Over” screen so that it detects when the level has been passed. I hadn't realized that. 😅
I'm glad you liked the infinite upgrades