Nice concept and good take on the theme of the jam. To further develop the game:
- You could add in an environment so the player isn't free to roam and has to navigate obstacles too.
- There could be higher priority targets which give more money.
- There could be hidden 'dangerous' targets which know how to fight back.
- There could be police patrolling where if they see you stab someone, they'll chase you and take your money (very realistic I know)
- After you stab someone, other people could run away, which makes it harder for you to catch them.
Overall good stuff!