I would say no because of this:
Gradually means more slowly and less dramatic.
Happily is more like joy and sometimes comes and goes very quickly
Hope this helps:)
Happily, victoriously, etc.
Jocularity, Jocular, Jollityor Jovial might do ...
Joyfuly, enthusiastically, gladly contently, cheerfully, gleefully, blissfully, merrily, with enthusiasm (luckily adv.)
more happily, most happily
Happily.
Happily, victoriously, etc.
gradually, or progressively.
Jocularity, Jocular, Jollityor Jovial might do ...
gently, calmly, gradually, moderately, unhurriedly
steadily, slowly, progressively, gently, unhurriedly
gradually, leisurely, unhurriedly, bit by bit, little by little
Joyfuly, enthusiastically, gladly contently, cheerfully, gleefully, blissfully, merrily, with enthusiasm (luckily adv.)
slow, steady, regular, measured, slow but sure, plodding, ongoing, continuing
Gradually reach or cause to reach a larger and larger area or more and more people.
Casual, unhurried, relaxed, easy, deliberate, languid, slow, gentle, calmly, gradually, without haste...
The comparative of Happily is more happily and superlative of happily is more happily
more happily, most happily