Halo: Spartan Strike ($6) + Halo: Spartan Assault ($6) — Microsoft has been putting a lot of effort into the iOS platform lately with significant updates to its Office suite of apps and the introduction of an entire family of MSN lifestyle apps, so it was probably inevitable that we’d eventually see the company enter the gaming side of things. This week, Microsoft released two of its Halo spinoffs, the original Halo: Spartan Assault, and the…