Let me say, at the start, I loved the original. Let's go back to basics on Sudden Strike II - you have to play God/General to either British, Russian, German, Japanese or US troops in various WWII scenarios (many authentic missions). In the campaign mode, each battle and objective progresses the war effort and so on. The maps are very large, larger than most RTS games and you really can get lost quite easily.
There are a wide range of soldiers and vehicles. Each type of soldier has a range of skills, and they are hugely different - for example - the sniper is a really useful tool, but you only ever have a few. Each also has their own health and experience levels, so you can select your elite troops to attack an enemy pocket, and they will do much better. You don't really have much control over the numbers of troops available - you are provided with your resources, and occasionally some fresh troops will arrive in your theatre of operations, but that is it. Use them wisely. Capturing enemy artillery and mortars can very often be the best route to victory, and essential for dominance. All the normal RTS functions are there - fog of war, group control, team selections and so on.
Detail is the name of the game here, and the detail is superb. Your troops are tiny on the screen, but that doesn't matter. It is things like having to get a truck to pull an artillery piece that makes the difference - you can get your men to pull it, but it takes an age. I find it too easy to get excited about the details of SSII - everything from repairing men and machines to hiding in bunkers is here. Your very own piece of war ... beautiful.
As you can see, I am a fanatic, so I must focus, and review, rather than ramble on about how great it all is. Ok, being objective, the sound is weird. The music is bizarre, and best turned off. The other battle sounds are good - tanks rolling into contact, random shots and the thumping of the arty, all great stuff, but not overwhelming considering the number of battles that might be raging concomitantly. The graphics are RTS style - you don't want too much, or your map would seize up. As it is, the game runs very smoothly. Just look at the system requirements and you'll see why - it only wants a 233 processor with 64Mb RAM, so basically your toaster will run it.
New additions in SSII are the Japanese option, 50 new vehicles, improved AI and ‘damage modelling'. Basically put, they've plugged the gaps from the original game to complete the picture. Having said that, it is almost identical - the control and the visuals are the same. Gamers will literally be able to keep playing - although the missions are now more structured.
In summary, if you liked the original, the you'll want to get the sequel - it deserves the time and attention and the challenge is still there - and it really is challenging. It might be a bit too much war geekery for some gamers, it does take time and strategy to win. If you are in any doubt, pick up the original second hand, and give it a go - the sequel is almost the same.