One catch: many trains cut passengers off from precious data services, restricting their mobile options. Another caveat is that the best games for commuters need to be playable with just one hand, in case you find yourself clinging to any available handlebar space. (Bonus points if you can play these games while balancing your morning coffee -- I'm not that good.)
You'll notice that this list excludes the ubiquitous Angry Birds because I found I can't achieve perfect trajectory while holding my phone sideways and swiping with one hand. Neither will you find more advanced games, like Cut the Rope, since some stages require multiple fingers for three-star accuracy. However, this list includes games from many different genres, so you're bound to find something that helps make your morning commute whiz by.
What are your favorite ways to kill time while commuting? Did we miss any of your favorite games? Let us know in the comments.