Sure thing.
- Enter desktop mode on your deck (Steam button > Shut down > Switch to desktop). Your deck will now load a linux desktop. This takes a few seconds and the controls will be unresponsive for a brief moment. Once everything finished loading you can use the right trackpad to move the cursor and R2/L2 for left/right click.
- Now you can download the game from itch.io (a browser should be pre-installed if i remember correctly).
- After the download has finished open the file explorer (which is called Dolphin in this case). The explorer should now display your home folder that also contains the Download folder.
- Find and extract the compressed file you downloaded. (Right-click > Extract > Auto-detect subfolders)
- Optional: move the unpacked folder from the download directory to your home directory.
- Open the game folder and find the game's executable, a file ending in ".sh". In your case it should be the file "BID.sh" if i remember correctly. Right-click the file an select Properties. Navigate to Permissions and enable the checkbox "executalble" and apply the changes. Info: this step can be skipped if you have a windows ".exe" file.
- Right-click the file again and select "Add to Steam".
- Close all windows and double-click the "Return to Gaming Mode" icon on the desktop.
- Back in the normal UI navigate to your Library and browse the tabs to find the non-Steam games. There you should find Bound in Desire. Probably named BID.sh or something similar.
- You can now bring up the game setting and give the game a propper name and change the resolution from native to 1024x640.
- If you want to run a native Windows game the process is the same, but you need to set the compatibility to "proton-experimental" and skip step 6.
I hope this works for you. If you have further questions feel free to ask.