Larva Mortus is a top-down shooter. You go from room to room killing everything with up to eight different weapons. You can level up your stats, play through tons of levels, or you could just play something else.
The biggest problem with LM is that the difficulty is unbalanced. When you select your difficult setting, you're actually deciding on how much you want to be annoyed. This game features a lot of small enemies, some that leave trails of fire everywhere, spit multiple projectiles, and even randomly become invincible. The harder difficulties mean you have to put up with more of their crap, blow through all of your ammo, and possibly get killed in the process. The easiest setting seems like the best choice, since all difficulty really affects is how much the player does and takes damage. However, this setting also makes the game too easy...which I guess is to be expected...hm. Regardless, the alternative is pointless frustration.
Insta-death also starts to become a common theme later in the game. Devils and Champion Knights have attacks that'll kill you regardless of health or difficulty. Circle-strafing is a good method of avoiding this deadly attack, but these jerks tend to attack in groups, and other enemies lending a hand. Still, death really isn't very punishing, unless of course you managed to collect a rare item. There are a number of unique treasures that strengthen the player or offer a big XP bonus. These are lost if you die before completing the stage. Strangely, all of the achievements are tied to these rarities, you don't even get a cheevo for beating the game.
Larva Mortus is just a very dull game. Within 15 minutes you've seen most everything the game has to offer, and yet it just keeps going for hours, without purpose or entertainment value. There are a few moments of satisfaction, like blowing up a half-dozen monsters with a cannon, or shooting a werewolf in the face with a shotgun, but you can get more entertainment from playing a classic FPS like Doom. This game consists of running through rooms, occasionally finding something interesting, sometimes dying, and just never really caring. Your free-time is more valuable than that.