You are absolutely right. I had an hour left before the deadline and I knew I wouldn't be able to make an ending, or at least the ending I wanted. The ending was supposed to be a Victory screen saying "Thanks for Playing!" (like you said), showing how many deaths the player did and how much time did it take them to complete. I should have made a very minimal version of the ending (like you said). However, seeing that almost everyone figured out where the finish line was and what the finish condition was, it leads me to believe that I did something right about the whole setup.
Thank you for sharing your thoughts, it means a lot!