Sequential target shooting, play must shoot in right order, how?

Let's say I've got 7 cans up on a shelf and I want the player to shoot them in the correct order... an order I specify at random at game start.

Coke, Pepsi, 7-Up, DrPepper, Fanta, Red Bull & Monster.

What's the most effective/efficient way to do this? Assuming I want to do two things later, increase the number of targets massively, thereby making the selection process more difficult, and add more targets later as the player shoots...

and one other thing, I want to get the information back about what they've hit wrongly... I want to know if they get confused by the choice between Pepsi and Coke for example, and post a cheeky message to the screen about one tasting better than the other, but the player being wrong in this instance.

Break it down.

Initialization

  • Randomize list of cans

Player hits a can

  • Check whether the can that was hit is the next in the list.
    • If it is go to the next in the list
    • If it isn't then show a message