Xbox Live Arcade is having a good day today, as the online marketplace for Xbox 360 downloadable games has picked up three new games. All three are available now at the price of 800 Microsoft Points ($10).

Gaia Industries' MLB Stickball arrives today as promised, featuring sandlot-style baseball and players with gigantic heads as inspired by Topps "Big Head" Major League Baseball Cards.

MLB Stickball, left; Beat'n Groovy, right

Tenchu: Shadow Assault is a party-game spinning off From Software's famous stealth-action Tenchu series. The self-described "trap action" game supports four-player multiplayer both on the same TV and over Xbox Live.

Beat'n Groovy, from developer Voltex, is a music-rhythm game using the standard Xbox 360 controller. The music library spans "different genres such as electronic, instrumental, and pop" and features two-player versus play both locally and on Xbox Live.

Gaia Industries' MLB Stickball marks this week's downloadable addition to the Xbox 360's Xbox Live Arcade portfolio, Microsoft and publisher 2K Sports confirmed today.

The baseball effort lets players pitch and hit to their heart's content in a variety of neighborhoods, each with their own custom rules.

Priced at 800 Microsoft Points ($10) and arriving Wednesday, October 8, MLB Stickball will also let players beef up their team with over 120 professionals by collecting in-game packs of Topps "Big Head" Major League Baseball Cards.