I've pretty much finished a game but I'm stuck trying to implement a final control. It's a scrolling, top down shoot them up based on the planet Mars. The game currently allows the player to move left and right, to also quickly switch back and forth between weapons and obviously to fire. The player can play with either WASD and space or use the cursor keys and ctrl etc. This part all works fine.

My problem is that a player can earn an extra power up that might allow him to fire a special weapon or it might be a shield the player can use to protect their ship or it might allow the ship to jump over some of the creatures that inhabit the game. I've tried using the following to activate the special feature:

• An extra key “E” sounds sensible but it's a bit of a manic game and I find it impossible to use intuitively while playing.
• I've tried altering the functionality of the up key “W” so, rather than switching weapons (there are 3 weapons), it activates the feature but obviously this leads to lots of mistakes.
• I tried the same with the down key. I get less mistakes as it's used less frequently but it's not perfect and it seems counter intuitive to press down to jump (if that's the current special feature).
• I tried adding the feature to the rotation of weapons which works well if the special feature is a weapon but is a bit counter intuitive if the feature is jumping.
• I might try just hitting any other key to activate the feature but that just seems messy.

Any thoughts?

Cheers Mike

How about holding the shoot button down for some time, to load up some power needed fro the special thing, then releasing it with letting go the button.

This was often done on home computer games where joysticks had only one button. Worked well for me to play.

A great idea but unfortunately the game really is a bit of a shooting frenzy so need to have the fire held down when dealing with masses of aliens while the player tries to switch between weapons to pick the best for what's coming at him. The player admittedly wouldn't have fire held down permanently as they'd quickly run out of ammo or would just be hit from fire reflecting of the alien shields.

Do you need the other hand to aim with the mouse or something?

The player, well actually just me so far, just plays with the WASD keys for direction and change of weapon while the other hand uses the space bar to shoot. It's a pretty standard set up. It's just the variation in function of the power up, special function, that makes it difficult to assign a control for.

Ok. I've asked because then i would map the special action to a key near the shooting button and use the same hand.

Actually i would remap your controls to use arrow buttons for movement and weapon switch, X for special, and Y to fire. I'm used to that from playing Super Mario, using X to run. It's pressed down almost all the time, and i can button mash Y for shooting while doing this well and comfortable. Many games would come with swapped XY defaults, but i would change this then.

Contrary, in a 3D shooter, looking around and aiming is the most important action. So i use the right hand for the mouse and accept to do WASD movement with the inferior left hand.

It seems your problem is about player habits? You want to find the best default settings?
Then you can add my preference to your collection of samples.

But other than that - it's not really your problem? Players can configure as they wish anyway?