I played this a lot for a while, mainly because the other topic existed and reminded me that this also existed. The only problem I have with it is that if you're on singleplayer, even with incredibly industrious AI, it's far too easy to make insane amounts of cash easily and there's that annoyingly tempting get-rich-quick fast forward button, and on multiplayer my impatience gets the better of me and I can't be bothered to compete with players who are clearly better than me and own rail links to every major industry on the map.
In short, with the fast forward button I'm useless :D
Not sure how to install this game, do I just download it along with the files labeled as free alternatives?
Download and use the installer. If you want the other optional/alternative files you have to throw them into the OTTD directory after installation (such as the music, original TTD graphics etc.).