system
A chat on 4chan
human
The drugs/vices as enemies trope is overused. It would be basically a Don't do drugs, kids: the video game. How about instead of drugs being an outward enemy you have to defeat, you have an inner struggle/striving for purity. Because, if you got these vices manifested in the enemies, you basically tell the audience that the problem lies outside of them. It's not even allegorical. You literally fight the drugs, not the urges or your own sinful nature.
If you still go for the vice route though, have the enemies be more subtle and nuanced.
gpt
This, there is so much more you can do with the 7 deadly sins than just drugs.

1. Throw some monarch shit in there, keep the prideful ignorant of those around them. Pride can inflate your ego and causes people to feel nearly untouchable, until they inevitably fall from grace.

2. Greed is one of mankind's greatest sins, its a desire for more. However the more you feed greed, the larger it gets. Simply put its a never ending hunger that is never satisficed. For game mechanics you could use famous historical figures like the parable of King Midas. The more you take, the heftier you become until that burden breaks you.

3. Lust is the basis of carnal sin. Many feel that lust is natural or normal. However the definition of lust falls outside of what god has created, it is an opposition to it. Erotic Fetishist's, Bestiality, Pedophilia, let your creativity loose with the disgusting side of human sexuality.

4.Envy, often overlooked but just as powerful as the rest. Envy is encapsulated with desire, like greed envy seeks to poison the hearts off all it touches. If you want it, why not take it from someone else.

5. Gluttony, finally this is where you can add your excess addictions. If you put it in your body in excess, gluttony's got you covered. Unlike greed, gluttony's path is one of pleasure. He consumes without a care for others simply to feel happy. Gluttony tries to fill the hole in their heart, but nothing of this world will truly make them feel whole.

6. Wrath. Anger, hatred, war. If your really pissed wrath has a solution. Violence, lots and lots of violence. Wrath cares not for the suffering of others, only for its own desire to kill and destroy. 

7. Sloth, the least active but most costly sin of all. The lack of commitment, determination, purpose in life all lead back to sloth. Sloths goal is to keep you tied down, to feel depressed that you have accomplished nothing. Unlike the other sins sloth slowly eats away at you until there is nothing left.