Moved as this isn't exactly a private matter.
As for your issue. What do you define as "how can I play"? How to "play" the game (control wise, etc) or how to play (launch) it once it is installed?
You need to own Half-Life (on steam) -> https://store.steampowered.com/app/70/HalfLife/ if you...
Not exactly quite true, as such I'd like to add some additional info to that.
It is true a lot (if not most) sounds were taken from DB(Z) franchise. But there are some sounds that may have been custom made specifically for ESF. Which sounds (effects) they are, I don't know. But in usage of...
@Daz_Falco You replied to a thread with the latest post being from 2006. Safe to say in those many years, the sites were shut down.
For port information, you can use sites like : https://portforward.com/half-life/ - https://support.steampowered.com/kb_article.php?ref=6470-EIFV-5481
Checked out some gameplay videos online regarding the update, and it looks pretty sweet. Almost keen to actually grab the game myself eventually. But I'd say the game will take up a lot of your time to actually get somewhere, ain't it.
You linked your forum account with steam, not half-life.
Though, the current half-life verification system is broken so you couldn't do it either way for the time being. Hopefully, will be resolved soon.