From memory, I saw this movie mid 90’s.
I’m not sure if it was in English, though I do remember thinking it was probably French when I tried to recall what it was later on. I watched it at home, so it was either on TV (probably SBS) or hired on VHS.
It was definitely in colour, without a sepia wash or anything like that. None of it was animated.
I remember a boy being left alone in what I think was a hotel room. He goes out into the corridor and gets on one of those fancy elevators that would normally have people operating them (the ones with the cage doors that slide to one side) and winds up on a beach with a giant bird (think Plucka Duck) who lives in an army tank.
He meets characters from Alice in Wonderland and falls in love with Alice as he grows up. The people in her group decide to try leaving in a hot air balloon, and he was going to go with them, but gets there too late.
The film ends with the much older boy (maybe 17?) and the giant bird sailing off into the ocean on a wooden raft.
If anyone else even remembers it at all, I’d be grateful.