This is the only version of the Frankenstein story where Frankenstein learns to love and accept his creation, rather than rejecting it, and it's thus also the only one where the story ends happily. The point at which the doctor understands that he's basically brought a baby into the world—a baby only he can take care of— it starts making you feel all warm and fuzzy inside.
Frankenstein: And listen to me, you are not evil, you... are... GOOD! Oh, this is a nice boy. This is a good boy. This is a mother's angel! And I want the world to know, once and for all and without any shame, that we LOVE HIM!
The Monster: For as long as I can remember people have hated me. They looked at my face and my body and they ran away in horror. In my loneliness I decided that if I could not inspire love, which is my deepest hope, I would instead cause fear. I live because this poor, half-crazed genius has given me life. He alone held an image of me as something beautiful and then, when it would have been easy enough to stay out of danger, he used his own body as a guinea pig to give me a calmer brain and a somewhat more sophisticated way of expressing myself.
As an added bonus to the first scene, that includes the scene where, after calling himself FRONK-en-steen and trying all manner of things to distance himself from his family legacy, he finally embraces it. The way Wilder says it leaves no doubt — he is no longer ashamed of who he is.
Fredrick: MY NAME...IS FRANKENSTEIIIIIIIN!
There's an element of wholesome-ness that the Monster's interaction with a little girl goes much more smoothly than (let's say) his previous incarnation. Although it's Played for Laughs when the little girl ends up catapulted into her own bed, that's by far one of the better conclusions of their interaction you can imagine.
From a production standpoint, Brooks went out of his way to dig up all the original mad science equipment from the 1931 classic film. If that doesn't say Affectionate Parody for you...
In addition, the set designer who created, and still had most of the props, was not credited in the original movie. Brooks made sure he was credited here.
Wilder wrote in his autobiography that he kept trying to find ways to add additional scenes to the shooting schedule because the cast had a thoroughly great time together and Wilder didn't want filming to end.
The above two facts, plus the fact that Mel Brooks insisted on keeping the film in black and white, the same style as the old classic Frankenstein movies - to the point where he took it away from Columbia Pictures when they insisted otherwise.
The gramophone will in the deleted scene does have some touching aspects (albeit ones which can cancel each other out), with the Baron's desire to see the family name reformed through Frederick and willing to shower his wealth upon everyone else if Frederick isn't a doctor.
The musical
The musical adds the blind man getting a happy ending, hooking up with Frau Blüchernote *WHINNY*.
