Battalion: Nemesis is not a game which is particularly coy about its origins. Indeed, the designer is quite upfront that he wanted to design a game which was very much like Advance Wars, and would hopefully improve upon it. I also enjoyed Advance Wars 2 very much, so I went in expecting to enjoy Battalion: Nemesis. While Battalion: Nemesis does deliver the fast-paced turn-based strategy action I expected, it sadly falls a little short of Advance Wars in the final analysis.
If you've played Advance Wars, you should be able to hop right in (with only a few aggravating differences to get used to); if you haven't, here's what to expect. Battalion: Nemesis is a simple turn-based strategy game, where you battle the enemy on land, at sea, and in the air with a variety of units, spanning pretty much what you would expect: some infantry, some tanks, some artillery, subs, battleships, fighters, bombers, and so forth. Most units are direct-fire units, which move next to an enemy and then attack them, after which the enemy (if it still exists) can return fire. Some units are indirect-fire units, which can attack enemies from a distance, but cannot fire and move in the same turn. Scattered across the map are oil refineries, which produce money, and factories, which produce different types of units; only infantry units (which are weak) can capture these properties, so careful coordination is required in a successful attack.
If you have played Advance Wars, you'll notice some differences right off. Many of these are simplifications: for instance, all logistic considerations (fuel and ammo) have been removed. This removes a dimension that many people find annoying, but I think is an important aspect of the game. Air power (possibly to compensate for the preceding) has been severely reduced; bombers especially are no longer close to the map-dominators they are in Advance Wars. (The elimination of fuel, though, is a great help to subs, which can now remain submerged full-time.) The COs have been eliminated, which I think is kind of a disappointment, since they're a nice touch. A bunch of unit types have been eliminated or their functions consolidated into other units, which results in a simplified but awfully sparse unit tree. There's no Fog of War, which I don't mind, since I never really liked it, although in the campaign the enemy will field stealth tanks against you (I guess they got them surplus from the Brotherhood of Nod). Finally, transport has also been simplified -- rather than requiring separate units, you can just summon a sea transport or air transport (at a cost) which will instantly appear to transport your unit. There are only a few things which aren't in Advance Wars -- there exist sea oil refineries, too, which can be captured by a new type of sea unit, there's (finally!) a sea unit which can engage in direct combat with other sea units, and you can repair units in the field rather than retreating to a city (properties don't, in fact, repair units any more). The most frustrating change, though, is that instead of moving a unit and then picking a target to attack (or undoing the move if you desire), as you do in Advance Wars, you move and attack all in one fell swoop. This resulted in a lot of missed moves for me, exacerbated by the fact that you can't undo. Probably this is less of a problem if you're not used to the Advance Wars format.
All of this combines to give the game an Advance Wars-lite feel, and the campaign just doesn't have the same sweep and scale that Advance Wars does. There's only ten missions in the campaign (plus six "boot camp" training missions and one bonus map), and since the first few of these are pretty easy, there's just not a lot of meat. Even in the later missions, the maps are still relatively small and often feel kind of cramped. (They do still take a while, though, especially since the AI runs really slowly on some of the last few missions -- sometimes it would take on the order of several minutes for the computer to move, which was really annoying.) All in all, the units just don't quite work as well together as in Advance Wars -- I found it more difficult to mount a good, large-scale assault. Maybe it's just because I didn't bother to learn the ins and outs of the different unit types as carefully (and there are a lot more things to keep track of), but it just doesn't feel quite as well-balanced as Advance Wars.
The graphics are not bad, employing the same slightly cartoony style as Advance Wars, although there aren't any combat animations -- just a "pow!" and a health bar decreasing, and then the same on the other side. The sound effects are not bad; at least they're nicely varied among the units. The music is decent -- there's not the variety that you see in Advance Wars, but at least you and the enemy have separate snippets to keep you from getting too bored.
In case it wasn't evident, I am a huge fan of Advance Wars, so there's no shame in falling slightly short of the target. And it may be simply a reflection of my familiarity with Advance Wars that I tend to favor it in the areas where it differs from Battalion: Nemesis. I did enjoy Battalion: Nemesis when I played it; it's just that it ends up being not quite as great as Advance Wars.