Hammerwatch is a game that feels like an old school (and intentionally looks like one) hack-and-slash game similar to Gauntlet. The story consists of one box of text at the beginning: "The small bridge broke behind you...there is probably no way out!" From there, your job is to kill and collect anything in your path and stay alive. When I was younger I used to play the hell out of the Nintendo 64 version of Gauntlet, it was fun when I took on the levels alone, but things really got going when a friend or three joined. Hammerwatch is similar. Due to the non-existent story, your motivation for moving forward is take your selected character from a choice of a Paladin, Warlock, Wizard and Ranger and take them to the end.
Playing alone, Hammerwatch is fun enough, fighting large groups of enemies as a lone Ranger, wiping out hundreds of bugs and creatures. The first act of the game is quite lengthy, where the constant killing and exploring for secrets slowly turns into looking for the way out. Fortunately there are save points around the world so when I began to burn out I could come back later refreshed and ready to go on. There are RPG elements in the game in the form of upgrading your attacks and adding in combos. At times I forgot that I could alter my skills, as it felt way too long between finding the vendors that I can purchase the skills from. Initially you have a basic attack and a special attack that feeds off of your magic meter. With combos added you gain bonuses such as health regeneration after killing 10 enemies in short time.
Going with old style pixel art, Hammerwatch pulls it off well and feels like a game you could have been playing in the 90's. The music works as well. For controls you can use the keyboard or controller. I recommend using a controller if you have one over using the keyboard. Not that the keyboard is a bad way to play, but I found dual sticks the way to go.
Playing co-op can be done by sharing the same screen or online. If you can, plug your computer/laptop up to a TV or have a big screen - sharing a screen can be good fun with a group of friends together. Online is great for if your friends aren't nearby or it's hard to get people together. The online experience isn't always smooth, there is stutter at times and a few graphical hiccups but neither really impact on the game and really I can't remember the last time I played an online game that ran super smooth so it's hard to knock Hammerwatch for the same.
If you feel that you are up to some level editing that is available too, you can tailor make levels that you and your friends will enjoy. If you just want to make the game harder or easier there are sliders to adjust.
There's not much to dislike about Hammerwatch unless you hate having fun, it's a fun Gauntlet style game; great fun with two to four people and fun enough playing it alone. Combined with some nice 'retro' visuals and good music to quest to, with the game editor you shouldn't run out of content anytime soon.