In my opinion, it is good to have something published and if it's good enough to be shown to the world, it should be good enough for your portfolio.
But that brings me to a different point. Develop a critical eye for your work. When you publish something on a digital distributor like XBLA, Steam, or even mobile devices, you need to be very critical of what you're showing the world. Potential employers, clients, and colleagues can all see what you've put out there and they will all use that work to determine your skills.
Be sure to polish the game play as much as possible.
Clean up and refine all of the graphics.
Make sure the audio is exact and clear.
Just be sure to check everything and make sure it is as great as can be and not just good enough.
But that's just my opinion.