I also like to play RTS games like StarCraft 2 and Red Alert 3. I prefere Terran in StarCraft 1+2 and Allies in all Red Alert games. I use completly different main strategies in all games.
I have played RTS games from the beginning like WarCraft 1, Dune 2 and Mega Lo Mania. I also have a copy of WarCraft 2 in a early alpha version. I also like turnbased games like Civilization series and Heroes of Might and Magic series.
In StarCraft 2 Terrans has several different unit types when compared to original StarCraft like more and better air to ground units and better infantry but mech builds are not equaly strong mainly since Siege Tanks are weaker and easier to hard counter and there are no cheap Vultures with Spidermines. The reactor addon gives new strategies like masspumping basic units in Zerg style and switching to techlabs for advanced units.
The original StarCraft has TV shows and professional teams but StarCraft II never reached the same mulitplayer popularety since the games is close, but still not as well balanced as StarCraft I. Many players like me therefore only play StarCraft II in Coop mode, and Coop + singleplay is what keeps the game popular. Blizzard has made both games free to play. But if you want StarCraft 1 in modern HD graphics you nead to pay extra. If you want to play some campaigns or use more than 1 basic StarCraft 2 Coop Commander per race you nead to buy them.
Even is one has bought StarCraft I, "StarCraft : Remastered" cost extra. And many StarCraft II Coop Commanders cost extra, as do Mission Packs, but it is worth it since Blizzard has high standard.
I also like to play co-op missions in StarCraft II as well where I play at Brutal difficulty. I started to play Co-op missions in summer 2018. Co-op missons are sort multiplay but with single play objectives and team play with a random human player vs computer. One can choose a number of Commanders to play as and the partner can not play the same Commander.
Every Commander requeres different strategies and has different strenghs and weaknesses. Some Commanders like "Karax" and "Swann" has for example strong static defence and some Commanders are vulnerabe towards certain units types like has weak anti air and other Commanders has very incredible expensive units or has weak units that are dependent on suicide tactics and some Commanders nead heavy micro.
Many players, like me, only play StarCraft II Coop and not regular StarCraft II multiplayer.
"Han and Horner" is a combination of cheap expendable units and mines backed up by expensive elite aircraft, including bombers, and strong calldowns.
"Han and Horner" has a weakness in unable to build anitground defence structures and are depend on mines for that purpose and "Han and Horner" also lacks a strong ground unit that can tank damage except Deimos Vikings to some extent but has on the other hand super Reapers, Widow mines, a special Raven version and a different anti armor Hellion + elite air units, especially Sovereign Battlecruisers and Asteria Wraiths and upgraded Strike Fighters can decimate large areas of ground units.
"Han and Horners" ground units are constructed from unique flying buildings called Galleons that can also doubles as combat units and can be upgraded to become a sort of Carriers. However max 5 Galleons can be supported and all Starport air units are locked on cooldown timers and max 10 Strike Fighers are supported.
"Raynor" is allround with very good infantry in form of Marines, Medics, Firebats and Marauders. "Raynors" Firebats are realy strong after upgrades and has like Marines and Marauders access to stimpacks like multiplayer Marines and Marauders. "Raynor" has also super bunkers. "Raynor" has also access Vultures , Siege Tanks, Vikings, Banshees and Battlecruisers but lacks a mobile detector.
"Raynor" is the only Terran Commander that can upgrade Command Centers to Orbital Command but can not mass pump Mules since one neads energy to scans as well to get detection. Note that in co-op "Raynor" can not call down extra supplies like in both multiplayer mode and in "Wings Of Liberty" campaign. "Raynor" can call down the Hyperion to fight for timed life span and also elite Banshess for a timed life span.
"Swann" can not build infantry units and play is mostly about enhanced mechs with strong upgrades and unique turrets and a powerfull upgradeable laserdrill.
"Swann" has also Hercules transports with tactical jump that partically makes Siege Tanks and Thors more mobile but even Goliaths, Hellbats and Cyclones can use them. "Swann" has also special Science Vessels and the underrated but massable Wraith fighter with special upgrades and "Swann" can also deploy drones that increases both players gas income.
"Swann" has the best Terran defence and also one of the games best defences.
"Nova" controls very expensive and small numbers of elite units that functions almost like "Wings of Libertys" mercenarie units but other unit types, names, stats and upgrades. "Nova" has powerfull but expensive calldowns and she also appears on the battlefield as a hero unit that can be upgraded. All of "Novas" units are locked on long cooldown timers that sometimes makes it impossible to build that unit type you wanted to deploy.
"Nova" does not have to build Supply Depots but can only use 100 supplys of units and has also automated refinerys and can also build an unique anti ground only turret.
"Tychus" is a cool Commander and has a complelty different design based on very powerfull and expensive heroes called Outlaws with expensive upgrades instead of an army. "Tychus" can can only build 5 Outlaws, at level 1 only 4 Outlaws, where one always gets "Tychus" and buys the other 4 from 8 different unique Outlaws where one must choose wisely depending on map and enemy composition since one can not regret a choice. "Tychus" does not have to build supply depots but has 100 max supply like "Nova" where Outlaws are 10 supply each.
Apart from Outlaws there are no others units to build except SCVs that can also build special turrets that attacks both ground and air acts as detectors. If a Outlaws die the unit will be restored for a cost at the "Joeyray's Bar" where Outlaws are build. The Outlaws are very powerfull and expensive and money goes to upgrading the Outlaws attack, armor + hitpoints and individual uniqe abilitys where primary individual ability gets better or given new abilitys or becoming detectors.
"Tychus" can call down the massive war machine "Odin" from "Wings of Liberty" campaign to fight for 60 seconds. "Tychus" has also medivac transports calldowns that gives him the games best mobilety and that also heals the Outlaws and also gives a short time cloaking field.
All Commanders starts at level starts at 1 and Commanders get more bonuses and more upgrades or unit types as one levels up. Once level 15 is reached one reaches start of Mastery level that all Commanders shares and gives additional unique bonuses. I am currently at Mastery level 89 where 90 is max for Commanders bonus points. After level 90 it is possible to level up even further but Commanders do not get stronger.
I have leveled up all Terran Commanders to Mastery level. I have also taken all of "Han and Horners" and "Raynors" and "Swanns" and "Novas" and "Tychus" archivment points.
I have recently started to level up all other Commanders as well becouse a good Commander can command any type of army and it will increase my understanding of the game. I have no goal in taking all Commanders archivment points, even throught I taken all Terran Commanders and also all of "Zagaras" and all of "Fenix" as well. I have already leveled up "Stukov" (infested Terran), "Karax" (Protoss), "Fenix" (Protoss), "Zagara" (Zerg), "Dehaka" (Zerg) and "Artanis" (Protoss) to Mastery level.
Of the Protoss Commanders I am leveling up towards Mastery level have "Vorazun" level 5 and "Alarak" level 10. Of the Zerg Commanders I am leveling up towards Mastery level I have "Kerrigan" level 5 and "Abathur" level 5.
I probebly handles the different Terran Commanders best despite that they all have big differences in game strategy. The most underrated Commander in the game from what I read at forums is the Zerg Commander "Zagara" but I belive she is good in the hands of the right player and I handles her pretty well.
The Commander that generally does not fit my natural game style is the Protoss Commander "Karax" unless on certain maps, but I have usually no problem working with a "Karax" partner regardless of map. I am no big fan of playing as infested Terran Commander "Stukov" either but I have him at Mastery level as well as "Karax".
All Commanders are free to play up to level 5 if one has bought the game, but I am not shure if all are playable if one only got free play mode. Of the Commanders I play "Raynor", "Swann", "Artanis", "Vorazun", "Kerrigan" and "Zagara" are free while I got "Fenix" and "Karax" and "Stukov" as a gifts from Blizzard. But I have bought "Nova", "Han and Horner","Tychus", "Dehaka" and "Alarak". In the future it will also buy "Abathur" but I will level up the other Commanders first.
"Artanis" is a basic Protoss Commander with many units from the original "Starcraft : Brood war". He can warp in units from all building into pylon power areas and also deploy a mobile pylon field and has strong calldowns as well.
"Fenix" is a little different. He appers as a Hero unit that can change between three forms. "Fenix" has a little different units and can also build hero versions of each unit types where max one per type can be deployed at a time. "Fenix" has an upgrade that renames him into "Talandar" as he did in the story during campaign but its more of an easter egg since the upgrade gives no bonuses from what I can tell. I have taken all "Fenix" archivment points even through one of them is stupid and discourges team play.
"Karax" has possible got the games best static defence and has strong calldowns and support abilities but hes unique units are realy expensive and costs more without being better than standard Protoss units. Once mastery level is reached one can spent some points to actually afford to build units, I spend a many points there but I also placed a lot to increase buildnings hp to enhance "Karax" natural strength and not create a new Commander.
"Vorazun" is based on Dark Templars and Corsairs supported by some other units anhd has special dark pylon calldowns that cloaks nearby units and structures. When one reaches enough level one can use timestop to freeze units and also to create a black hole.
"Alarak" is based on a hero leading unique ground based Protoss troops but can call down a Death Fleet with timed life once one reaches enough level. "Alaraks" Zealot versions are called Supplicant and are cheap and comes 2 at the time and they are automatical sacrificed to give "Alarak" health if "Alarak" is near death. "Alaraks" units sometimes behave different than visually similar standard Protoss counterparts and has other unique upgrades as well.
"Kerrigan" is a basic Zerg Commander with many units from the original "Starcraft : Brood war" and appears as a strong hero unit.
"Zagara" is a simplified Zerg Commander with very few unit types and more easy economi since drones spawns in pairs. She also appears as a hero unit. Her units spawns fast and are very cheap but has 100 max supply and are dependent on suicide tactics from Banelings and Scourge to win the game by raw swarming and respawning. She can also calldown a number of Roaches and a number of Hunter Killer (hero Hydralisks) with a timed life and can attack be sending a number Banelings from herself. The number of spawned units depend on hero level. Also note that Baneling nests spawns free Banelings based on timer. I have taken all her archivment points but I can think ones neads some well placed Mastery Points to make a few doable.
"Stukov" is based on sending wave after wave of infested troops, where some basic troops are free, supported by calldowns that creates temporary super units. Infantry has a timed life while vechles, infested bunkers and flying units are permanent.
"Dehaka" is a special zerg that does not nead of has overlords. He has unique units knows as "Primal Zerg" and has similar standard Zerg counterparts but with other stats, upgrades and costs. "Dehaka" appers as a hero unit that can be leveled up with essence and has a unique way of building units, like Barracks with queued units that can be constucted, and units can evolve themself into other types of units by merging, one can in some cases choose if it going to be flying unit or a stronger ground unit. "Dehaka" can also call down a number of hero units with timed life and has unique defence buidings/units that can deep tunnel into new positions.
I have not played "Abathur" enough yet to to give a complete coverage of him. "Abathur" seems to be able to level up hes units with biomass to level up indivuduell units hp and attack and when the unit has enough biomoss evolve to ultimate evolutions.
In the Red Alert games, the Allies has completly different strengths and weaknesses in each games. The Allies strength in Red Alert 1 is better Navy and the Light Tank. In Red Alert 2 I use a combination of units and in Red Alert 3 the Allies has the superior Air Force. I also prefere USA in C&C Generals due to superior Air Force.