What the minigames do
Two things at once:
- Earn money — the economic layer of the game
- Raise Harvey's mood — required for the True Ending
And one thing the interface does not tell you: each one damages his psyche.
Whack-a-Harvey
A classic whack-a-mole format. Harvey pops up, you hit him, you get paid. Fast-paced and brutal, and the most direct restatement of the original game's loop.
The other torture simulators
Several more are available. Each one feeds a player's desire for entertainment while Harvey suffers.
You are doing to Harvey what the real players did to him in BLOODMONEY! 1. The game hands you the same loop, one layer up, and waits to see whether you notice.
How this fits the endings
You cannot reach the True Ending without maintaining Harvey's mood, and you maintain his mood through these games. The game does not offer a clean path — caring for him properly requires participating in the thing that is destroying him.
Neglecting mood entirely, alongside letting his food bar drop, leads to the Dead Ending.