Super Robot Taisen BX (also styled SRW BX) is a Japan-only tactical role-playing game in the Super Robot Wars series. A short informational piece about downloading it (legally and safely):
Using a Prepaid Card: You'll need a Japanese prepaid card for the eShop to purchase the game. Download Super Robot Taisen BX -Japan- -Rev 1-
Super Robot Taisen BX is a Japanese-exclusive tactical RPG released for the Nintendo 3DS Overview — Download Super Robot Taisen BX -Japan-
The gaming landscape has moved to the Nintendo Switch and PC, but Super Robot Taisen BX (Rev 1) remains a high-water mark for 2D sprite work. Download Super Robot Taisen BX -Japan- -Rev 1-