As we've often said before, pre-ordering is a publisher ruse designed to get people to pay for games before they can be warned if they're no good. Just think how great all those lucky people who pre-ordered Aliens: Colonial Marines are feeling right now. 11 Bit Studios, the indie team behind Anomaly Warzone Earth are taking the concept from the ridiculous to the ludicrous. You can pre-order their next game for 50% off... until they announce what it is.
Yes, clearly it's a marketing stunt by a small team. And of course this isn't the same league as Major Publisher asking you to pre-order Game X for the same 10% off everywhere will be offering in the first week of sale anyway. This is an indie looking to get attention, and some financial support.
If you pre-order whatever it is before the 28th, you'll get the game for half price, and access to its beta in late March. The game itself should be out by the Summer. And as they say,
"If you're not sure whether you're willing to pay for the game, we ask that you please just wait until we actually announce it. Sure, you'll pay full price, but this deal is for those brave souls who are willing to jump into the abyss with us and take a chance on a mystery."
All that's known at the moment is this teaser: