Cowboys & Aliens
now available in the Android Market. It's only $3 but considering it looks like a simple 2D java game that's about the most it's worth.
It's a 2D side scroller with a a d-pad and a few action buttons. It feels very dated with very low fps animation that's completely outdated on a smartphone.
It works on my Nexus S but force closes on my ASUS Transformer.