Rather than execute to the end, my if () then block appears to stop execution.

See http://scratch.mit.edu.ezproxyberklee.flo.org/projects/10742289/

What am I missing…?

You're doing too much in the whack event. Just record the hit there. You need to move the show hide logic into the when green flag clicked event and have a loop (eg repeat until moles = 5) in there to do all the show and hiding. I can see what you're trying to do but it's not a good way to go. Basically you don't want an event to be running (the whack event) when you could receive another one.

If you want some ideas then look at this fruit splat game which was written for version 1.4 but has a similar idea. All the control for what appears and when is in the Stage.

Thanks for your reply but I don't understand how to put hide/show code in the startup block

I need to act on the whack event as well as record it. If I don't do it in the event (where it logically belongs) then how do I trigger the actions?

Will check out the fruit splat thanks. (Please note that no actual moles are harmed playing my game)

Remixed here. Still not perfect but hopefully gives you an idea to progress.

Thanks, I moved the detecting which mole was hit to the hammer sprite (as in Fruit Splat) and used separate broadcast messages to each mole.

It now seems to work pretty well but I'm going to try putting my moles into an array, so the code isn't duplicated,

Version 2 is much better, with cloned moles appearing at random across the lawn
http://scratch.mit.edu.ezproxyberklee.flo.org/projects/10755214/