Built on the Unreal Engine, the first thing you'll note about Choplifter HD is that, well… it's high definition. The original flat, sprite-based chopper of the classic is replaced by fully rendered three-dimensional choppers. But despite the jump from 2D look to 3D world, Choplifter HD sticks to its side-scrolling roots. 

Using the left analog stick, you can move the chopper up, down, left, or right. Choplifter HD will feature three aircraft types -- the light, fast Sparrow; the larger, slower Raven; and the Navajo. In the early demo inXile brought to PAX, only the Sparrow and the Raven were playable. Each had individual stats, strengths, and weaknesses, which made using them feel dramatically different. The Sparrow was quick, but small, only able to hold a handful of passengers. The Raven on the other hand was heavier, quite slower than the smaller chopper, yet had more than double the number of seats. 

Since you'll be facing resistance on your missions, it's fortunate that you've got a machine gun and missiles on your side. Aiming a laser sight with your right analog stick, you'll be able to take out enemies with a limited number of missiles and put holes into everything until your gun overheats. While you'd expect to take fire from the sides in the 2D-scrolling shooter, inXile has added enemies into the foreground, as well. Tapping the left or right bumpers on your controller, you can turn the chopper and fire into the frontline. While it was easy enough to move the chopper up, down, left, and right, this foreground shifting mechanic took a few moments to get used to. But once I got the hang of it, I was quickly turning my chopper in all directions, giving any opposition what for. 

While the main goal of many missions is pick up and transport (yes, you can land on and kill passengers if you're not careful), inXile is switching up missions in a number of ways. In one, I had to drop off and then protect an agent as he ran into a building to plant explosives. After doing this in three key buildings, the location of hostages were revealed, opening up the second set of goals towards mission completion. Other mission variants could include timed objectives, and there's even something involving zombies that inXile isn't ready to tell us about just yet. 

In one of the three levels inXile brought to PAX, I ran into a familiar face: Duke Nukem. Landing next to Duke, I found that he wouldn't get in my helicopter. Apparently, it wasn't up to his standards. But Silva tells me that choosing the right chopper, Duke may hop in. Other videogame characters are set to make appearances, as well, including Super Meat Boy. 

Another thing to note: chickens are not safe in Choplifter HD. I landed my chopper in a crowd of chickens, causing them to startle and scatter. As they did, they got caught in the blades of the helicopter with expected results. (Yes, you'll get bonus points for this at the end of your missions.) Poor chickens. 

Choplifter HD is scheduled for a fall release for Xbox Live Arcade, PlayStation Network, and PC.