"Play your own music", Molly Maggot says as it boots up, which doesn't create high hopes for its quality. The clunky jumping controls, stilted animations and lifeless goals soon solidify that sense that you're sifting through trash. Save for a few sound effects that are almost funny, Molly Maggot doesn't have a single notable quality.
In Molly Maggot you play as a maggot chewing through a corpse. The body is displayed as a 2D maze of sorts, with your character able to chew through one square chunk of flesh at a time. Some chunks are distorted or overly-decayed, and any contact with these will damage you, as will running into the other weird creatures inhabiting the body. Three hits will send you back to the start of the stage, which can be a few areas back; if you manage to chew your way to an exit, you get to move onto the next maze.
To help you along, orbs are randomly strewn through each area. Popping these will let you gain and strengthen new moves like being able to spit slime or do a flying corkscrew-like attack. They'll also let you refill your health, but you have to choose that over a possible upgrade; these are rarely in the same place twice, so all you can do is hope they're along your path as you work your way through the level.
Here is where we already run into some problems. Each stage is fixed, so finding the best route to the exit is important and the only way you'll make it far in the game. Since there is typically an optimum path, you have to hope that some upgrades just choose to appear on your way. They might or might not, making it hard for you to survive later on based on random chance, which seems like an odd decision given that the actual path to the exit is fixed.
Upgrades are likely moved about at random to encourage exploration, but they can easily appear in places where it would be suicide to go for them. Even if they're not in an extremely dangerous position, deviating from the best path will often put you in a bad spot due to the controls and stage layouts.
As mentioned before the world is built of flesh blocks you can chew through - the problem is that you can easily chew your way to a place you can't escape from, and there's nothing you can do besides wait for an enemy or bad piece of flesh to kill you. Until you know the layout of each level, this will happen constantly. The game does include a look function that will let you scan the area, but it doesn't help much as it only lets you see a short distance away. It might look safe to drop from where you are right now, but you'll likely find almost no way out upon landing.
You'll also want to minimize exploration through the game world because the jumping controls are miserable. Most paths get you stuck because they are lined with blocks of damaging flesh, but you can't carefully jump around them. Jumping typically only works to leap up, not forward, making you fight with the game to get it to leap in your direction of choice. Most times when you want to leap over a damaging block you just hop up and land right on top of it. You could try to corkscrew past it, but you might not actually have that power if an orb didn't decide to appear on your path.
Maybe some of this would be worth fighting with if the game were enjoyable. Without any music it ultimately feels lifeless and silent. The occasional chewing sound effect doesn't do much for the gameplay as you poke around, trying to find the best route through a dead body so that you can go through a door and chew through more lifeless body. Eventually you'll screw up and die, having to go back multiple areas (each stage is split into a couple of areas) and do it all over again. Doing this in silence just feels like work, and playing your own music won't likely fix that sensation.
A few bosses and new enemies give you something to strive for, but your ability to endure bad jumping and dull exploration are all that will keep you playing Molly Maggot. If you're desperate to see how miserable life as a maggot is then the game will provide you some context, but otherwise it's a boring, joyless slog.