Lacking real depth, this small expansion will kick your butt over and over as you keep coming back for more.
The first thing you'll notice is that it's a bit tricky to access the content, at least I was confused for about thirty seconds: Both of the levels that come with this Vietnam expansion are under the "Challenges" section of the game, not the "Adventure" section. The two levels you get include an objective-based linear map, and a survival map. The Survival map is quite simple: You're tasked with surviving against super-strong Vietnam Goblins and Soldiers (Yes, Vietnam Goblins), and the objective-based level is similar to the original game in that you follow a linear path to complete the level.
The graphics are completely the same as the original; pretty nice textures and models, and more than above-average effects for your magic attacks; something I've felt was absolutely astounding for an independent game of this caliber. The gameplay is the same as well, save for the fact that now you get to use Machine Guns and Rifles to subdue your Vietnam foes in addition to your traditional armaments of swords and staves. The difficulty seems about the same for the most part, though it does tend to seem like you can get yourself killed much easier when the bullets begin flying all around you; I still highly recommend this for Co-Op.
The length of it is up for debate, as the main level is pretty short in and of itself; lasting less than a mere hour even when you try an extend it out. But, then again, you can find this for sale for five bucks ($5), so I guess you get what you pay for. The Survival Map is simply a map in which you fight waves of Goblins and Soldiers over and over again, which is to be expected of course. Since the original game was only ten dollars ($10), some could say that costing 50% of the original price tag should make the expansion longer, but you can also argue that taking it at face value, a five dollar ($5) add-on is expected to give you five dollars ($5) worth of content; debate, debate.
Overall, I would say that for five dollars ($5), this is a very interesting little "expansion" that gives the lovers of Magicka (myself included) a chance to continue their adventure. It's always a good feeling to be able to support hard-working independent game developers who can produce a gem like this. And although it isn't the world's best game, it does give you a good amount of time to have fun killing Goblins in the Jungles of Vietnam.