I will buy Warcraft 1, but is it worth to buy?

It's very basic. So your mileage may very greatly on how much you actually get from it unless your a huge Warcraft fan.

I heard Warcraft 1 very slowly, isn't it?

I don't know about slow (i never found it slow, plus i think there are speed values like in 2), but it certainly is older, the graphics are worse and most convenient shortcuts/commands, like right click in 2, are absent.

Still, though, it is a timeless classic!

Warcraft mouse helper is your... helper. Seriously, it adds most of the modern day functionalities, especially RMB working as we are used to.

Thank you, bro.

I personally could never get into it. It's not just because the graphics are primitive, the rest of the game is as well. That's not to say that it's a bad game, but if you're used to playing more recent games, even WC2, it's likely to be disappointing.

The graphics only allow you to see a small area of the game at a time, you've got the standard limit on how many units you can select at a time with no ability to assign them to a hot key. It also seemed to lack the charm and humor of the sequel.

Personally, I got it, because I got it because I still had the discs and wanted to get rid of them. But realistically, it's been the better part of three decades and I haven't yet felt compelled to play for more than a few minutes.
But, YMMV. The RMB stuff was a byproduct of the game needing to work on Mac OS as well as PC with relatively few changes. The age of it is probably the other big factor.

At this point though, this kind of utility is just nice to have. It's unlikely that many people are going to be playing cross platform network games on both platforms.

play it once for the feeling and the original classic sound files

I definitely wouldn't recommend it to anyone who hasn't played it before. Even those who have may not want to revisit (with or without modding). The "story" is also as basic/generic as it gets. Just stick with WC2.

Pretty much. If one is going to play it though, it's probably best to play it before WC2. My big mistake was that I got it in the Battle Box and had both immediately. I think I would have fonder memories with it if the sequel hadn't been so good.

Another great utility from pcgamingwiki. I love that site more and more. Thanks for letting us know, Ghorpm! +1

Despite playing Warcraft II first, I managed to enjoy its predecessor for what it is. But yes, those are some major drawbacks that you mentioned. I wouldn't fault anyone for getting frustrated with the super-dated interface, the inability to build additional Town Halls, etc. Due to these and other challenges, I only committed to finishing both campaigns - I don't recall playing a single custom game all the way to the end. Moreover, I'll readily admit that I save scummed like crazy (damn those sneaky AI catapults). One major incentive for playing was the ability to summon creatures, a feature that younger me thought was painfully missing from the second game. Ironically enough, when I belatedly got my hands on the third game a decade later, the youthful novelty of summoning Water Elementals and other creatures had died down.

I liked WC1. It had nice graphics and gameplay for the time and a kind of unrefined charm somewhat lost in WC2.

But compared to modern titles, it's very basic.
Warcraft2 was already superior to it.