Kingdom of the Wind
Kingdom of the Wind is another game by Rudy Sudarto, the designer behind Epic War (review here), and apparently he decided it was a successful enough formula that he didn't need to change it very much, because Kingdom of the Wind is a very similar game. Frankly, I disagree with this -- by the end of the game, the formula here will feel very stale indeed, and it could really use a change of pace to make the game more interesting.
Anyway, so you have a floating castle you need to defend from a relentless enemy. You have mana, which you use to buy units. Your mana regenerates gradually over time, and killing enemy units also gives you more mana. In addition to units, you can spend money on upgrading your units' abilities, or on increasing your mana pool and regeneration rate. Unlike your typical game of this genre, there's no enemy side to destroy; rather, you just have to survive each level for a given amount of time. Usually, though, you reach a point of equilibrium at which you can easily survive indefinitely before you reach the end of the level, so there's often some twiddling of thumbs while you wait for the timer to finish. At the end of a level, you get XP for enemies defeated and units created which you can then use to buy various upgrades and unlock new units; unlike the similar upgrades you can buy in battle, these are permanent.
Like many games of this genre, one of the more annoying features is that you often spend a lot of time simply waiting for your mana to accumulate. (Unlike Epic War, there aren't even any arrows for you to shoot.) The behavior of the units is also not entirely understandable -- while I am glad to see a game of this type where the units don't simply advance in a line (the battlefield is pleasingly two-dimensional), sometimes your units will hang back towards your castle and sometimes your units will venture far forward to attack, and often what they do is the opposite of what you want them to do, and it's hard to tell why exactly they're doing one thing and not the other. (In the later levels, I found myself relying more heavily on turrets simply because I could count on them not to wander off.) One particularly unforgiveable design flaw is that buying the increased initial mana upgrade is actually harmful -- it means you'll have to pay more for every increase in the mana pool (and hence mana regeneration), which is really, really annoying.
The game is pretty tricky in the initial levels -- I died more than a couple of times in the first few levels -- but once you get the hang of the strategy, and have purchased some of the basic upgrades, the game becomes noticeably easier, so the last few levels are not particularly interesting. Fortunately, there's only eight levels in all, so the game doesn't take too long, but there's even still a lot of dead time toward the end of the game. The graphics are OK -- each unit is pretty nice-looking, but they're pretty small, and there's not anything in the way of attack animations; they just shoot colored balls at each other. The music is, much like Epic War, kind of stirring in a fantasy movie kind of way, but does get repetitive. The sound effects are pretty poor; they're just generic zapping noises and don't add very much to the game.
Overall, Kingdom of the Wind really needs something new to be an interesting game. It's not too long, so if you're just in it for the points (or challenge), it's not too bad, as long as you don't buy the increased initial mana upgrade, but the design is simply not interesting enough to make it an engaging game.