At the gnarled and gore-encrusted heart of Hammerwatch is a combo system of pleasing simplicity. To trigger it, you must kill a bunch of enemies very quickly, and then once it's in motion, you can upgrade it in a number of straightforward ways - to deal 360-degree damage, say, or to heal. You can build it, too, by killing more enemies. It's action game design at its most basic, and it works.
In order to feed the combos, Hammerwatch needs to ensure that you have plenty of enemies to massacre at all times - and this is a favour it's very happy to grant. Grubs, skeletons, wandering eyeballs: these standard fantasy baddies wait for you in packs around every corner, spawning from pits or rotten tree trunks or mysterious fountains. Along with a standard attack, each character has a special that can generally be counted on to do a lot of damage at once, and so, as you move from combo to combo, a pleasant rhythm settles in. Throw yourself into the fray to power yourself up. Get into trouble so you can get out of trouble again.
Around this central relationship is a game of equal simplicity, a straight-up dungeon-crawl in the spirit of Gauntlet. There's a handful of familiar character classes (the paladin's a melee tank with a deadly dash, for example, while the wizard's low on health but just look at the flames he can conjure); there's the lightest trace of a backstory (the bridge has collapsed behind you, so why not keep going, eh?); and the bulk of the game consists of working your way up through a series of stacked dungeons, eviscerating baddies, standing on rune-splattered pressure plates to unlock secret areas or open the path to the boss, grabbing all the gold you can find, and then using your spoils to make you incrementally better at eviscerating baddies.