Sounds haven't changed a lot, there are the usual in game sound effects, no improvements noticed on that area, the same for crowd sounds but opening music isn't as cool as Song2 and no, there are no supported sound APIs such as EAX or A3D 2 for taking advantage of those cool Vortex 2 and Live! sound cards.
Interface isn't something of what I like to talk about, it's very similar to the previous ones, options haven't changed drastically either, there has been added a quick match option that lets you get on a match with less than 3 clicks while in the other hand penalty shootout has been removed, that was one feature I liked a lot.
Multiplayer via TCP/IP is not present, there are only options for LAN and a modem game, I tried modem play and it wasn't very nice, with WC98 I was very pleased with modem play but in Fifa 99 there is way too much lag, of course, multiplayer on the same machine is available.
Now, what really matters, gameplay...
This is the biggest improvement in Fifa 99, gameplay is fassst as in real world and there is an option to make it even faster if you want. There are a couple of new modes of play, sure, the classic Friendly Mode, Quick Game Mode, Training Mode, a new Golden Goal mode, the first team that scores wins the match, and also there is now the European Dream league with the best clubes of Europe, you'll find this a very nice feature.
Fifa 99 is much challenging now, and the computer will not make any stupid moves like in Fifa 98, as always there are 3 skills, Amateur which will become very easy after playing a couple of times, Professional which requires you to behave you much more than before but if you are an experienced gamer you'l also beat this skill, and no, it's not easy.... and finally World Class in which you'll really have to practice and here's where the real
challenge comes, this skill is damn difficult, winning a game wasn't easy and required some effort, no, I haven't been able to win a cup on World Class yet... sometimes playing in World Class will end on some frustration and you may prefer to switch back to professional that offers a good balance of gameplay.
Finally I can say that Fifa 99 rocks ! - This is one of those games that will stay installed for a long time on my HD, great graphics, excellent AI and kick ass gameplay, very addictive !