Mozart in this film is portrayed as a musical genius there is no doubt about that, and I agree with such an approach, but he is also portrayed as an incredibly immature man, who has many child like qualities. Hulce does do this to a very loud extent. He makes Mozart very flamboyant and purposely obnoxious at times. I do actually like the way he does this. Yes he can be annoying but Mozart is suppose to be that way. He is always appropriately loud and vulgar and his performance serves as a clever contrast to the proper way of everyone else in the court scenes in particular. I feel he has the right playful approach to the character that I find works quite well. perfectly and serves the film very well. By the way his laugh is annoying but it works I feel that Hulce does not over do and make the character single feature ever during these scenes. This is part of Mozart completely and clearly but not the only part.
He makes Mozart's talent believable despite being an immature fellow. He always does show a little more to Mozart than his normal immature way. I like how he shows that his talent is something natural, and everything he does which is considered musical genius is just something easy for him. Despite seeming odd and improbable it never is to me, and Hulce helps in that greatly by always being convincing. He has the right amount of pompousness as Mozart. Always touting himself as the best composer in Vienna and his work as the greatest. He usually stays fairly upfront and to the point but I like one scene where he cleverly tells Salieri he is terrible in the guise that he is unique, and like no other. Hulce delivers those lines particularly well. I also enjoy the scenes where he honestly tries to push his musical ideas rather than just boasting about them. He is excellent in the way he honestly puts fourth his music in two scenes to the Emperor. He has the right passion and honesty to make these scenes work.
The best part of Mozart's performance is how he slowly changes and sort of decays throughout the film. I like how is slowly and subtlety loses his joyful ways. Not all at once but perfectly changing. He stops being as eccentric or as wild and as he calms down a madness of sorts also arises. Hulce is just perfect in the way he slowly and deliberately reduces the fun the character has. It never is overt but always underplayed making it so Mozart's slow demise is completely convincing. He like Abraham excels in his final scene well writing the requiem. Both actors are perfect in this scene and both are essential in making the scene as effective as it is. He is basically dead in these scene and Hulce shows that well but he also presents his an emotionally effective last scene where he has finally completely run out of humor no longer even his laugh. Hulce is good throughout and great at the end. I do not think he is as great as Abraham but few performances are. He still stands out for me and is another contribution to making Amadeus the great film it is.