So I've been a huge fan of the Klonoa franchise since I was young, which was why I was drawn to this title. I was partly inspired to try out rom hacking from Slowbeef (notably of Retsupurae and 'Let's Plays' in general). I've also previously done translations for a couple manga.
I got my start reading a few documents from this site about creating tables and relative searching. I eventually figured out the table and started by replacing most of the Japanese alphabet with a new English font and then changed the text to English wording. I used Tile Molester Pro for tile extraction/insertion and Translhextion for hex editing. Mednafen was my emulator of choice, and its debugger helped me find where the compressed tiles for the 'Best Time' katakana on the level select was located.
The main issue I encountered was how the Wonderswan puts together different tiles. Alot of the tiles show 'smearing artifacts' (notably on menus and the cutscene font) when reinserted and I'm not sure what causes this.
A huge help came from one of the game's features of saving the last room you were in and letting you continue it from the title screen. This allowed me to easily make changes to the rom and then continue without having to play an entire level over again, notably for the end of world cutscenes.
Credits were pretty straightforward, although it took a few hours.
The level select screen took a little longer to make sure the new tiles matched closely to the original background.
Despite it being still incomplete, I'm very proud of the work I accomplished.
I also added the original Japanese and new English tables to the archive above.