I would really like to have a system whereby certain sounds (player conversation responses) can only be triggered by key presses when other sounds are not currently playing (npc conversation responses) but I'm not sure how to do this. I think I must be missing something obvious...

Any help would be greatly appreciated.

Wow! Thanks very much for taking the time to do that. I'll try using that method straight away. Much appreciated.

Unfortunately, the problem is still there however I get him to move.

The juddering only occurs when the assistant is following the player at the same time as the screen is scrolling (it's set to follow the player). When the backdrop is stationary (at either end of the level) there is no problem.

Thanks for the quick reply! I'll try that.

I'm a complete beginner and I'm probably overlooking something very simple here, but I'd be really grateful for some assistance.

I'm making a basic platformer in which the lead character is followed by an assistant. I've currently got the assistant to follow by having the system compare their x coordinates and set the action of the follower to left/right if he's too far away from the player or stop if he's within 20.

It works perfectly except that if you keep walking while he is following you, his sprite 'judders' very noticeably while he walks. I adjusted it so that the game only checked the relative positions every few seconds (thinking that maybe the problem was that it was constantly checking and restarting his walk cycle) but it made no difference. Where am I going wrong?

Thanks in advance for all help.