A lot of games are playable without understanding japanese.
I made a good selection here, in the middle of the page, clic on each cover to open an article : https://paderetro.com/2014/12/27/le-guide-du-newbie-de-la-wonderswan/ (in french, but it google translate quite well).
If you're not very "trial and error", remove Blue Wing Blitz, Dragon Ball, Inuyasha, Namco Super Wars, the two One Piece Treasure Wars, Super Robot Taisen Compact 3, the two Trump Collection and Uchuu Senkan Yamato. 48 games left. ^^