levels are gigantic (dockyard) or incredibly complex (the apartment in the 4th level or the theatre) and there's either no maps to use, or they're so worthless that it's the same as not having them, if you have a bad sense of direction enjoy wandering around like a retard for entire hours (i did)
the melee combat suffers from not having any tech to it, fists are the closest to having some variety in their attacks, but past that it boils to either get melees that one-shot (fire axe), or hit hard and fast enough to bring any enemy down to the finisher threshold (pistol whipping and fire extinguishers as an example).
the enemies are a 1:1 copy of doom enemies and there's no depth to them, their behavior is justified by le "hahaha they're dumb goons" gag
which makes the stealth bad, the only way to truly "stealth kill" someone is to sneak up behind them, do a very slow attack (that can miss), and hope that the KO'd guys don't get spotted, because they will get back up if another enemy spots them, worsend by the sprite-based artstyle + the capacity of hearing you if you aren't crouched makes going around enemies un-necessarily hard.
the gunplay is overly complicated for the type of game it's in:
- to get a gun, you either find it on the ground with a full mag/drum/whatever, or you silently KO enemies that have the guns in question (killing them while they're alerted or with loud methods will make them drop a broken gun instead), and get them with a random amount of bullets in the clip/mag/whatever.
- to shoot a gun accurately, you need to stand still and wait for the movement-based spread mechanic, but even if you do stand still only two guns will be pin-point accurate, rest will still be stuck with a noticeable amount of spread, and unless it's the tommy or the shotgun, you're supposed to headshot sprite-based enemies that might be desynced to their hitboxes.
- to reload a gun you have to find speedloaders/individual bullets and shells, but the issue is that you have to waste one or two of your three inventory slots to hold either or both of these, and no enemies drop any ammo you can use.