After Sony found some success in the free-to-play model (EVE Online: Dust 514, the plethora of games in PlayStation Home) it would seem like a no-brainer that Microsoft would dip their feet into this popular form of gaming. Teaming up with Toylogic (who helped out on Super Smash Bros. Brawl) the big M's first foray into F2P-modeled gaming has come to fruition in Happy Wars.
The basis of Happy Wars is fairly simply: a tower-defense war between two parties of fifteen online gamers takes place on a field. The first one to infiltrate the enemies' castle and smash apart their totem-poled Big Tower wins the battle. Of course it's not that easy; you simply cannot just mosey into the castle and take the win.