2.5d platform shooting controls?

Simple question really but I'm having a hard time deciding on what controls to use for the shooting. I haven't played many platformers on PC so this may come up as a simple test. Would using the arrows key make more sense to use or would the mouse it self be better?
Please explain as well.

Plaftormers tend to not work very well on a keyboard. As long as you limit the buttons, wasd and aim with the mouse should be fine. But if you're going to make a more advanced platform game, the keyboard is going to get frustrating.

It's also a bad idea to make a game to make a game genre that you aren't familiar with. Go spend a couple days playing a variety of platform games to get a feel for them. You can't make good decisions about control if you don't know what people are expecting. It's a really good idea in general to play a wide variety of games. It may sound silly, but a lot of game developers tell you to play games if you want to get into the game industry. If you've ever tried to make a game with people who don't game, you'll understand why.

I would highly advise you to add controller support. People who play platform games on the computer tend to have controllers for it. I have a logitech game pad for playing games like BroForce, Demonsoul, MtG, etc.

The above poster is right. It does somewhat depend on your game's focus. If it all about shooting and action, then I would design it with angled directional shooting at specific 45/90 angles so that you can work simply with the 8 directions(combining up/down/left/right). Then I would make it easy to change the controls to use any given gamepad. The "default" control configuration would have to be on the keyboard, and could be something based around the arrows and ZXC, or based on WASD and maybe JKL or similar for action buttons. But in any case, games like this should always be set up to allow the player to choose controls, as they shouldn't have to think about how to do things in the middle of a firefight.

I do play a lot of platformers just not on the PC. That was my main problem that I seemed to be facing. The game my dev team and I want to create is a 2.5d platformer like super metroid (but 3d). The problem is we weren't sure how to control the shooting, I said the arrows made more sense, another guy said mouse. So I just wanted some feed back to pick the correct path.
ps thank you for the joy stick information.
Thank you for the help

The thing is, if you depend on the mouse, you get some pros and cons.

Pros, you get to control aim directly where you want, meaning you can be less merciful on the player as far as the approaches enemies take, where the come from, how fast they are, because the player can aim directly using the mouse.

Cons, You can't easily use a game pad anymore. Game pads work on axes and so trying to control an aiming gun, shoot, and move at the same time will be much more complicated. If you instead follow the 8directional thing, where the moving also controls the aiming direction, you simplify things enough. But you then lose a bit of control as far as aiming direction. You also have to remember that you'd have to somehow animate the aiming most likely, meaning rotating something instead of directly controlling the angle.

In my opinion, in a shooting action platformer(like Metroid) you are better off without the mouse. I think the ability to use a game pad is much more important than being able to aim in slightly more directions. Also, you can always move around to get that 45degree shot at something, and in an action game are likely moving around anyway.

thank you that will be the approach I take.