Considering this is a fighting game, and most fighting games are better with gamepads, it would make sense to include gamepad support for this game.
If there are too many buttons, you could do a button combination system like for example if I were to use a ps3 controller I could press square for punch, l1 + square for a medium punch and l2 + square for heavy punch. take a look at tera online or final fantasy 14's controller scheme, I think something similar to that could work very well for esf.
I have not installed half life 1 for a long time, so I am not sure but they may even have gamepad support for it by now. I know there is gamepad support for half life 2 and that works really well, so perhaps you could even take a look at that portion of the source code and try to implement it into esf in some way. I am assuming valve might have added gamepad support for half life 1 already however. If that is the case, then it should be hardly any effort at all to include a default gamepad template for xbox 360 gamepads.
Finally, if you do manage to pull off gamepad support. To ensure everyone can get their controllers to work, you might want to recommend in your faq that people use motionjoy to trick their pc into thinking their gamepad is an xbox 360 controller. That way you could make use of xinput in esf.
I apologise if this is already planned or has already been suggested, but I think it is a very good idea considering it will be much better using a gamepad to pull off combos than it will be to use the keyboard. Of course you would then have to consider that the gamepad users have an advantage over the keyboard and mouse users when it comes to pulling off combos. But the keyboard and mouse users also have the advantage that they can use the mouse to look around a lot faster than gamepad users, and be more precise with their aiming aswell. This means they would have a bigger advantage when using energy attacks, could make the multiplayer gameplay very interesting. Truth is that both sources of input have their pros and cons, so no matter whether you are using gamepad or not the game is still going to be fair on yourself and other users.
Please consider this idea if you have not already, I think adding gamepad support will not hurt your game at all and only improve your game and attract more players. Especially gamers that like to play on the big screen from a couch, and prefer to use a gamepad when doing that.
If there are too many buttons, you could do a button combination system like for example if I were to use a ps3 controller I could press square for punch, l1 + square for a medium punch and l2 + square for heavy punch. take a look at tera online or final fantasy 14's controller scheme, I think something similar to that could work very well for esf.
I have not installed half life 1 for a long time, so I am not sure but they may even have gamepad support for it by now. I know there is gamepad support for half life 2 and that works really well, so perhaps you could even take a look at that portion of the source code and try to implement it into esf in some way. I am assuming valve might have added gamepad support for half life 1 already however. If that is the case, then it should be hardly any effort at all to include a default gamepad template for xbox 360 gamepads.
Finally, if you do manage to pull off gamepad support. To ensure everyone can get their controllers to work, you might want to recommend in your faq that people use motionjoy to trick their pc into thinking their gamepad is an xbox 360 controller. That way you could make use of xinput in esf.
I apologise if this is already planned or has already been suggested, but I think it is a very good idea considering it will be much better using a gamepad to pull off combos than it will be to use the keyboard. Of course you would then have to consider that the gamepad users have an advantage over the keyboard and mouse users when it comes to pulling off combos. But the keyboard and mouse users also have the advantage that they can use the mouse to look around a lot faster than gamepad users, and be more precise with their aiming aswell. This means they would have a bigger advantage when using energy attacks, could make the multiplayer gameplay very interesting. Truth is that both sources of input have their pros and cons, so no matter whether you are using gamepad or not the game is still going to be fair on yourself and other users.
Please consider this idea if you have not already, I think adding gamepad support will not hurt your game at all and only improve your game and attract more players. Especially gamers that like to play on the big screen from a couch, and prefer to use a gamepad when doing that.