Code Name: S.T.E.A.M.‘s release date is set for the May 15th, but today Nintendo has thrown a demo for the game up on the Nintendo eShop.
The demo itself takes up 1871 blocks, so if you plan on buying the full game (which is likely to be much larger), make sure to clear up some space on your SD card.
Code Name: S.T.E.A.M. is developed by Intelligent Systems, the same developer behind games like Fire Emblem. During the latest Nintendo Direct, there was plenty of information regarding it such as a new trailer and amiibo functionality details.
The demo itself is only limited to 30 uses, so play wisely!