Yes, it’s a zombie film, of sorts — and was made in the 28 Days of February 2010 (according to the makers).
Here’s the trailer:
The Invisible Atomic Monsters From Mars (UK-2010; dir. Tim Hunt and Adrian Pinsent)
And here’s the full version, all 74:33 minutes of it! Enjoy! It works best if you go to full-screen mode. Otherwise the ads that keep popping up get rather annoying!
Thanks to Avery Guerra for finding this low-budget gem.