If you want to bypass (or if it just does not launch) the homeworld launcher and play directly one of the 2 remastered versions you'll need to make a shortctut to the HomeworldRM.exe located in
.....\HomeworldRemasterdCollection\HomeworldRM\Bin\ReleaseEOS\
Then add the following parameters in your shortcut "target" line
for Homeworld1 Remastered :
-dlccampaign HW1Campaign.big -campaign HomeworldClassic -moviepath DataHW1Campaign
for Homeworld2 Remastered :
-dlccampaign HW2Campaign.big -campaign Ascension -moviepath DataHW2Campaign
without those and only launching from HomeworldRM.exe will make the single player option (basically the campaign) unavailable.
so by example for homeworld, the target line should look like :
.....\HomeworldRemasterdCollection\HomeworldRM\Bin\ReleaseEOS\HomeworldRM.exe -dlccampaign HW1Campaign.big -campaign HomeworldClassic -moviepath DataHW1Campaign
Note, in case you want to use the "playerpatch" mod (
https://www.moddb.com/mods/homeworld-remastered-players-patch ) that adds tons of bugfixes that the latest steam-epic patch didn't added, and still want to bypass the gearbox homeworld launcher, the parameters you'll need to add are a bit longer :
for Homeworld1 Remastered :
-dlccampaign HW1Campaign.big -campaign HomeworldClassic -moviepath DataHW1Campaign -workshopmod 2.3PlayersPatch\2.3PlayersPatch.big
for Homeworld2 Remastered :
-dlccampaign HW2Campaign.big -campaign Ascension -moviepath DataHW2Campaign -workshopmod 2.3PlayersPatch\2.3PlayersPatch.big
For the classic Homeworld 1 and 2, just using their own executable in their game directory should launch the games, it's only for the remastered version that you'll need to edit the shortcut to bypass the launcher