This review was conducted on a Samsung Galaxy SIII running Android 4.1.2.
Kingdom Rush is a fantasy tower-defence game for Android. No, wait, come back. I know we've seen a lot of these, but really, it's rather good. It's not original in any way, but it's got great artwork, doesn't take itself too seriously, and, most importantly, it understands its platform (but more on that later).
By now explaining the mechanics of a tower defence game is perhaps a bit unnecessary - we all know the rules, as Paxman might say - but it's probably worth pinning down the game's idiosyncrasies. KR eschews ideas of mazing (that is, placing towers freely in such a way that the enemies must take a longer path to navigate around them) and instead opts for pre-set paths and tower positions. There are four such towers: archers, who fire rapidly but do small amounts of physical damage; mages, who fire slowly but do large amounts of magical damage; artillery, which does large amounts of area-of-effect physical damage; and barracks, which produce hapless troops sent out to engage and slow the invaders. Each of these towers can be built and upgraded a number of times with gold picked from the pockets of fallen foes (automatically, mind - no Plants vs Zombies coin-clicking). At the highest upgrade level, you can choose one of two final destinations into which your tower can morph - for example, the barracks can become either a temple producing durable paladins, or a hut producing high-damage barbarians. Each of these final-level upgrades have themselves a number of abilities that must be unlocked for each tower - instantly disintegrating an enemy, for instance, or a large-area carpet bomb. While these additions (eight towers and around sixteen abilities) are hardly overwhelming in their complexity, they're enough to keep the levels lively and avoid the needless over-complication often seen in games with a more dizzying variety of towers.