Alexander: Total War.
NOTE: Your phalangists can't be retrained until you capture Issus, where the border of Syria and Turkey is now.
Your strategy should be to take the Mediterranean settlements and Babylon first, leaving the Persians pitiful and penniless! THEN aim toward Bactria, while sending a large enough army to deal with Scythia on the way. It may also be helpful to place your capital in the centre of your empire, to reduce maintenance costs. OK, now into the technical stuff.
UNITS:
The units in the game are, frankly, superb. The average units are hoplites, covered in bronze armour and with shields and spears to suit any occasion. These fellas work on hills as well as they do on a flood plain. Though slow-moving, you will thank them when the Persian heavy cavalry charge at you.
Then, there are the hypaspists. These are much like skirmishers cum light infantry. They have several javelins, which, when thrown, do a considerable amount of damage to formations of light cavalry, chariots and light infantry. So, basically the backbone of the Persian army. When hypaspists charge at Persian Infantry (an actual unit's name - basically spearmen with wicker shields.) it seems like an act of the Gods. They work as nearly a screening force or a barricade against any units that try to get to your other units.
Units such as the Agrianian Javelinmen, the only skirmishing unit you have and expert at killing missile cavalry and holding back light infantry, but their use is not enough to justify having a lot on the field. They are similar in cost to hypaspists and take one turn to complete, like them. For this reason, I would recommend brining them from Hellas(they'll turn into veterans if you use them right!), but don't try and get more once they're gone.
You would be much better off, in the bigger settlements, recruiting Phalangists, the ultimate hoplite. They take 2 turns to complete, but this is justified, seeing as they're about 4 times better than ordinary hoplites. These guys will take anything, bite it, spit it out and step on it. And that's the things they LIKE! If you have even 3 units of these guys in your frontline, you'd better hope the enemy like dying!!! However, these guys aren't invincible. They might need some support from the cavalry, which I'll focus on now.
Podromoi are the first cavalry you can train. They are best used for chasing down enemy archers and slingers, but not much else. They lack any javelins and are poorly armoured and thus almost useless.
Slightly handier are the auxiliary Thracian cavalry, javelin-wielding missile cavalry who are weaker than podromoi, but strong enough to kill missile infantry anyway.
Allied cavalry come next, a good supporting cavalry unit at last! Now, these guys are heavy cavalry, meaning you can charge them straight at the Persian and barbarian front lines and do massive damage(just check they don't have spearmen where you're aiming, though!) to their ranks.
Even they, however, aren't a patch on companion cavalry, the elite cavalry. You can't recruit them without a huge city, though, unless there are mercenaries around Issus(which there normally are). These guys are best aimed directly at the heavy cavalry and phrygian mercenaries(who are armed with axes and dangerous to any units, even Allied cavalry). Most of the time they can send Greek mercenaries running, too!
Then, there's the general's bodyguard. They're pretty much Companions with a family member. If you have any heavy cavalry, keep these guys out of the way, behind your phalances and spearmen. Their job is to keep your men brave, not to carge in and kill themselves. Don't use these guys unless forced.This brings us smoothly to another type of general.
Alexander's bodyguard. These guys can obliterate any other unit in two charges. With these guys, if you have no heavy cavalry, send Alex out to rhe edge of the Persian front line and charge from the side. The left as seen from the front is normally best. You're looking for the side with light infantry, heavy cavalry. Never, by any means, go after the general with these guys, unless everyone else has run away on their side. Point I'm trying to make is these guys are awesome.
O.K, so, that about raps it up. feel free to leave comments with me.