ioticus: I like to know how long I've played, so is there a way to launch the HD mod within Galaxy so I can use the mod and also know how long I've played?
CRW: That's pretty simple.
Just create a HD EXE (Heroes 3 HD) from HD Mod launcher, then navigate into Heroes 3 directory, rename Heroes 3.exe to something else (like Heroes 33.exe) and Heroes 3 HD.exe to Heroes 3.exe.
Now you will be able to launch it from Galaxy as well as trace your time played.
I found another method.
https://www.gog.com/forum/heroes_of_might_and_magic_series/heroes_iii_with_hd_mod_era_2_through_the_gog_galaxy_launcher Here's an adapted quote from the thread:
Exit entirely from the Galaxy client. Edit the "gogame-xxxxxxxxxx.info" in the game's directory and replace Heroes3.exe with "Heroes3 HD.exe", should be like this:
"name": "Heroes of Might and Magic 3 Complete",
"path": "Heroes3 HD.exe",
"type": "FileTask"
Now when push the Play button, opens Heroes 3 HD.
I found that renaming Heroes3 HD.exe to "Heroes3.exe" has a lot of issues. Low Frame-rate, lots of audio stutters...
Modifying the .info file is much better as there are no more performance issues and now I can launch any mod from GOG galaxy without having to rename the exe files.