Recently we put up a couple of gameplay videos, and hopefully that helps answer a lot of the questions right there. But if you're not into videos, or still have questions, read on.
When you first start a new game, it takes you through a brief tutorial level that also contains a goodly bit of story. On "new game plus," it skips these levels. Once you're past the tutorial, you emerge into the first overworld area, the Phoenix Forest.
The Phoenix Forest is the first of nine main overworld areas. Each one contains a number of required levels in it, as well as some bonus levels that are hidden and/or harder. Not all of the overworld areas are accessible in a single playthrough, as the story branches. And one overworld area isn't available at all until new game plus.
What Are These Levels?
The levels themselves are basically what you're seeing in the videos linked above. A single level typically has you coming in with no weapons or tools, and then having to make do with whatever you can find in the level. They're basically environmental puzzles, and many of them have multiple solutions.
There are also bonus objectives on each level that you can complete to get a better score and a gold marker outside the level. These bonus objectives are a lot more challenging, and generally also require knowledge of the level to complete, so you won't do them on your first try. New game plus remembers all your scores and level completion statuses, which is handy.
Each level usually has the goal of killing all the grays (zombies) inside it, although sometimes your goal is just to escape or to kill any one evil animal or similar. The grays are only weak to iron, water, and fire, so things like regular bullets don't hurt them. However, you can use a handgun (or if you later find it, a rifle) to stun them momentarily. Those same guns can be used to kill hostile animals or other creatures.
Lots Of Variety
There are almost 100 levels in the game, and there's twelve main weapons as well as thirteen main tools, and a handful of other items. There are also some levels where you use the environment itself to kill grays in novel ways, such as stunning them with your whip so they get caught in an avalanche, or pulling a lever that causes a trapdoor to open.
A lot of the tools and weapons can be used in multiple ways, or combined to create novel effects. As one example the lantern can be used to light your way, or it can be used to set sticks and so forth on fire. Grenades are useful for their initial blast, but also for creating holes behind them. Shovels can dig through dirt walls, or fill in those same kinds of holes the grenades leave. Hmm. And so on.
The styles of levels vary pretty widely, too. Some are incredibly head-scratchingly tricky. Often those are bonus levels. Some are a little more reflex-oriented, and aren't really much of a puzzle at all. Others are mazes, others are logic puzzles.
The vast majority, however, are tactical engagements where you get dropped into hostile territory, grab for weapons and other deterrents, and then set about dismantling the enemy in the most efficient manner than occurs to you. Rather like being a lone special forces dude dropped into a hot zone. All of the levels are hand-crafted to make this as interesting and varied as possible.
During the alpha and beta we ran, one of the big things that kept coming up was how cool the atmosphere of the game is. The graphics and lighting, and in particular the writing and music and sound work, combine to create a world that is decidedly creepy and mildly unsettling. There are a few segments that will get your pulse going more, in particular related to story events that you probably won't see coming.
The story itself is a bit unusual, in that it's about adults looking out for their families, rather than adolescent adventurers out to save the world. These people don't want to be out doing what they are doing, but they're forced into it by circumstances. That's interesting to me, and it also affects the general tone and mood.
Full Level Editor
All the levels in the game were created by an in-game level editor that is included with the game. It's right there on the main menu. It's a little complex, particularly if you get into scripting events or cutscenes, but it's also possible to do some straightforward stuff pretty easily. The key thing is that it's extremely powerful, so for people who really get into this they can create some entire stories and adventures of their own.
And that's about it!