The first thing that's strange about Total Annihilation for a newcomer is all of the different mods and expansion packs. There is TA: Escalation, TA: Zero, TA: Frenzy, TA:esc which covers most of them. It's not like Starcraft where people just play one game. It's like people playing StarCraft WoL, Hots, and LotV but there isn't a single version that is the most played or has the largest userbase. A lot of the popular mods are unofficial ones that were created by fans of the game.
I go on GameRanger to play other people and at first I tried practicing against the computer to get a flow of the game better. A lot of TA's estrangement for a person that comes from a Starcraft background is the lack of hotkeys and how the flow of combat is so different.
There aren't any building hotkeys so you do everything by mouse but that is more than made up for the fact that you can queue up buildings and there isn't a limit to how much you can waypoint a unit. Location hotkeys are kind of iffy. You have to reach all the way over to f5-f8, you can't use any of the other hotkeys before f5 even though they don't serve a purpose critical to the gameplay, just really miscellaneous stuff like pausing the game, bringing the out the game options menu, etc. that can change places with the f5-f8 keys.
You can select what feels like infinity units to one control group which feels nice. When you have a group selected and want to add more units you hold shift and box over the units you wanted to add in. However, if some of your already selected units get caught in the box when you hold shift they get deselected. You recall a control group by selecting it and then pressing T.
Method of Attack
The strangest thing is the attack method isn't as straightforward like in StarCraft. In StarCraft you get some units and issue them an attack command to a certain location. If they come across any enemies during their attack route they'll attack them. In TA the units don't get aggro'd like that, instead they shoot the ground endlessly without stopping even when there are other units killing them.
Most units can move while they shoot so you give them the move command and that's like the attack command of Total Annihilation. Sometimes you can hit stop and they'll attack a unit if they're in range but you have to hit stop on a lot of units individually or lasso small groups of 2-3 of them at a time because some will be in a conga line and pushed up against each other not getting in range so it becomes a mess.
You can also directly have all units selected and select attack an enemy unit and they will follow that unit until it's dead. Then they'll be on the stop command by default and kill anything else that's in range. It's troublesome sometimes because you're not really sure if you targeted it. In StarCraft if you hover your cursor over an enemy unit a circle with some design starts rotating around the unit and sometimes it'll blink on and off once or twice to show you've selected it but there isn't any indication like that in TA.
A lot of projectiles work strangely. When a unit shoots it's always a projectile and when it fires at a unit it fires at where the unit was when the projectile was first launched. So it's like having a stalker and when that stalker shoots a marine and the marine moves left the shot will miss the marine. It's never instantaneous like how a marine or a siege tank attacks. The micro works well in that way and creates some depth and compliments the use of using the move command to attack units.
You have two resources: energy and metal. Metal isn't as easy to get because you need to build a metal extractor over a metal patch that fits the size of a metal extractor perfectly so one metal patch=one metal extractor. You have to find multiple metal patches across the map to put metal extractors over. With energy extractors you can pretty much place them anywhere and you can line them up more neatly. The resources and expanding is spread out a lot so you end up having to get some static defense peppered in every few meters. Laser turret, the most basic static defence is a good choice along with a radar tower to see units in the fog of war.
I got really far behind other opponents I played. When you play a game a lot it becomes second nature to do something consistently but when you're only starting out you get some inconsistencies and blips in your worker production. It's like the start of starcraft and you aren't always making workers even if you have the money in the first minute which costs you a lot of money. I'd have lots of units inactive so my workers weren't building metal extractors and laser turrets and some fighting units across the map and I'd get really outclassed in a few seconds.
When you build stuff money is spent in small increments with the progress of the building. It's not spent instantly the moment you start the building. It's common for a newb to have a building that is 50 percent done but not generating enough resources to finish it so you're using up more metal/energy than you're producing and that is a huge setback. It's like having a command center 99 percent done and cancelling it in the first 4 minutes. It is hard to sort of predict if you can make a building because you end up having to estimate kinda cuz the amount of metal or energy you start with doesn't equate to how much you'll have at the end because you'll still be generating more of those resources during that time. Really good macro will have you be keeping metal and energy dangerously low sometimes. When you get the build orders down though it's pretty much smooth sailing.
It's a pretty fun game with a lot of diversity and quirks in units and strategies. It's strange how the community is shaped into several branches. I don't know many that play the official expansion packs rather than the fan mods which is a foreign concept to me coming from starcraft. It's a nice experience in how far RTS has come. :o