I got this game in a bundle and originally had it in my trades list, however, I decided to give it a try because I needed a mindless, time-filler in between games. I was pleasantly surprised by Hero of the Kingdom, and was happy to have given it a chance.
If you like super casual, short, adventure games that are less action-oriented (the game's main mechanic is item/resource management), then you will enjoy this game. It is easily beatable in less than 2 hours, and within 4 hours I had farmed all of the achievements.
The aesthetics are nice - the backgrounds are well-done and the menus/feedback are non-intrusive. The music and sounds are good, adding an appropriate feel to the atmosphere. The story and pacing of the game allow for a very mindless, non-taxing gameplay experience. After playing through a lot of time-intensive, mind-numbing games, having casual alternatives like Hero o the Kingdom is always appreciated.
The controls are extremely simple, as everything is done through mouse clicks. The tutorial is quick and painless, and the learning curve is mostly minimal - the most difficult element being proper item/resource management. It is pretty challenging to actually "fail" in the game, as there are always options for you to acquire more resources, even if you find yourself suddenly depleted of everything.
Gameplay is mostly linear and follows a straightforward formula - in order for you to progress to area X, you need items Y and Z. Item Y can be obtained by either buying it directly with gold, or by harvesting and crafting components A and C, Item Z is a side-quest reward. Variations of this formula occur, but the general concept is to have the appropriate items for each mission. Any form of resource harvesting (ex: farming, hunting) requires health points (and usually some other item(s)), and you are able to accumulate an infinite amount of HP if you keep resting.
For achievement hunters, this game is pretty easy to achieve 100%, however, a large amount of time will be spent finding small objects (mushrooms, crates, etc) on the screen. I had to do this in bursts, as my eyes and brain would get tired of searching through each level.
If you want a casual, non-demanding break from your typical games, then definitely give Hero of the Kingdom a try. I've played web-based games on sites like Newgrounds and Kongregate since I was a child, and this game has similar appeal as the quality titles you can find on there.
I normally try not to mention game price in my reviews, however, I would recommend most people to wait for this one to go on sale, or at least be bundled (as it happens often).
DJSF @DJSF's Rogue Reviews