Tennis GBC is more playable characters than Tennis GBA
Just like in Mario Kart DS and Mario Kart 7?
Different. Mario Tennis GBC had 9 Playable Mario characters, but Tennis GBA had only 6 them. Tennis GBC Courts had obtainable N64 theme courts and removed same background. Tennis GBA Courts had no GCN theme courts. Only have Peach Dome, but this is not special court.