Shadows of doubt feels similar to old school Deus Ex. $30 normal price, so wait for a sale.
You run around a dark rainy city as an ex cop turned freelance detective.
Take up small side jobs, break into buildings, make phone calls, buy coffee, listen to jazz in your apartment, read about a murder in the paper, sneak into a bloody crime scene to gather clues, hack computers, make a tangled conspiracy board, drink stolen alcohol until you're staggering down alleys, have crazed monologues, get an epiphany, track down a suspect, accuse them of murder, arrest them, close the case, find out they were innocent after all, repeat