Apologies for all the controller issues recently! There are 2 different problems going on, one of which is hopefully fixed for good now.

1) Steam introduced Steam Input which changes how gamepads are handled. Steam Input creates a virtual gamepad that interfaces with games to help with cross-platform and gamepad compatibility. Unfortunately, there have been some weird side effects with some setups including input lag, double inputs, and more. You can disable this and use Chasm's built in gamepad support by disabling Steam Input. Right click Chasm in your library, go to Properties, then Controller. In the drop down select "Disable Steam Input". Note this will only apply to this game and not the rest of your library.

2) Chasm uses SDL for low level functions like input handling, audio, etc. SDL's gamepad mapping file has entries for nearly every controller out there, so if you start the game up there's a good chance it will work right away. Problems began though when the community started adding new mappings for the PS4 controller and others that were incorrect. This caused the d-pad and other buttons to stop working or be mapped incorrectly. An update has just been released to remove the duplicate invalid mappings.

Please let me know if you still having trouble after updating to the latest on the community forums!

Thanks,
James