D3 Publisher's Simple DS Vol. 29: THE Sports Daishuugo (The Big Sports Assembly) is exactly like Wii Sports. Except it doesn't look as good, has different sports, doesn't have any kind of motion controls, is probably lacking in polish to the point of glitchiness, and nobody's ever heard of it. But outside of those and probably some other things, the two are the same.
THE Sports Daishuugo contains five main games: baseball, golf, volleyball, tennis, and futsal, as well as minigame variations on all of those. Like any decent casual sports game, it allows for multiplayer-- four-player single-card play.
We're actually surprised by how bad this doesn't look. The characters are cute and the graphics are non-awful. We wonder if this cute sports game will take off in Japan, where Wii Sports sells tons as a standalone product.