Puzzle game. Sure, it has the mechanics and theming of a tactics game, but there’s no resources/unit-building like Advance Wars (the units you’re given in a level is all you have to work with), nor are there any reinforcements or random-chances (thank goodness) like in other tactics games; the only range on stats is for how far away units can attack from. On top of this, many levels require specific actions to win–to the point the game even previews where enemies plan on going if you mouse-over them (they can be blocked if another unit stops there first), as many levels require you to bait enemies towards/away from things. In fact, you can even undo individual unit actions, even going back to previous turns or back to the start of the battle! This helps with less-than-intuitive parts because if you get caught off-guard by the fact that moving onto traps means you can’t attack with that unit or you didn’t realize locked enemies can still attack units next to them, you can just click the back arrow and try again without starting the level over.
Although there are some tricky levels here and there, most of the puzzles aren’t too difficult. Even the “++” campaigns don’t always bring the difficulty up much further than the main campaigns. Some maps can seem long and complicated at first, but more often than not, you’ll find that your first instincts on where to send units will only require minor adjustments at best to achieve victory. That said, some levels have optional objectives, but they’re not told to you in-game; they’re only mentioned in the game’s achievement list on Steam, so you wouldn’t even know they’re there until you get one by accident or you go out of your way to check the list when you’re not playing. It’s also sporadic which levels have them, so you’re probably better off just beating the campaigns normally and going back for achievements afterward. Plus, two achievements are glitched (and have been for years): the “beat Monster++ 19 with five units alive” is triggered simply for beating that level at all (even if you only have two units left), and the “kill all enemies in Monster++ 16” is awarded for beating Monster++ 4 (a different level).
Overall, its okay. I can recommend it since it’s free.