First post on the Dungeon forums (and in a thread about Order of Shadows no less!) so please be gentle:
I recently played this using an emulator as part of a chronological/timeline inspired play through of the Castlevania series that I am currently doing and in all honesty, it is really not all that bad, especially given the automatic limitations of trying to do a Castlevania game for phones of that period.
That said, I wouldn't want to even try and play it on an actual phone, but even just playing it on a laptop using the keyboard and the controls were really quiet manageable. Even the strange jump mechanics weren't a problem and can actually be quite useful once you know how to exploit them.
Not sure about the feasibility of porting the game to a cartridge though - I did a quick google and there was talk of a device for playing Java games on the GBA from years ago, but all links seem to be dead now.