The solution is not at the end of the game!
Using the blue screen as a ramp was not intendet. You can only peek over the wall, but I guess you will never be able to jump on the wall!
I know, it's kinda frustrating to see that there might be more... and you can't reach it.
Let me give you a little tipp: There is a "hint" in the very first room of the game ;)
I guess no one has gotten to the real ending yet... you could be the first ;)