They keep increasing the number of grunt player units you have. They're not great, but they can take some hits, draw enemy fire, and often have one or two shots of a decent weapon they can fire off. Using them well can make the stages a bit easier.
The Meltrandi in this stage are tough, but Misty comes in to help out after a while.
One interesting thing about this game is how few of the stages are just your guys vs. an enemy force. Most of the time there are NPC federation units, or a double enemy (Meltrandi and Zentradi, fighting each other and you).
This is another stage where we have to prevent the enemies from getting to the town. The enemies are somewhat strong, but overall the mission was OK.
This is more fighting against Lyle. It's a short mission because all you have to do is get Kiryuu to the edge of the map. I killed some of the units but then just bailed out when things looked bad.
Now Misty has officially joined the team. She and Kiryuu have the best final upgrade mechs at level 18, but that won't happen for a while. Incidentally, this game gets much easier when people get to their final upgrades (particularly Misty, Kiryuu, Guy, and Grey). A lot of people have Armored Valkyrie as a final upgrade choice but they're not very good.
Another relatively easy stage, with both Zentradi and Meltrandi.
This is it for the Meltrandi, another three way fight with tons of NPC units. Not a hard stage because of everything going on.
The traitor Lyle is back to fight us again. Maria has joined, a daughter of Max and Milia. I think she may have been in the previous Macross 2036 game; there's really no development of her character at all.
The video also contains a failure of stage 19.
This is the hardest stage so far (I'm up to 26 now). The problem is that there are a lot of tough units in the initial set, and then there are reinforcements with tough units as well. Getting Kiryuu or Misty to level 18 before this stage would help a lot. As it is, I stayed near the center of the map and fought the units as they got close. This let things go slowly enough that I was able to use all my PC grunts to absorb hits and do a little damage, and even though I lost some units, I did win in the end.
Lyle has now joined the team. He's the best unit after Kiryuu and Misty, and also gets a nice upgrade at level 18. Those three can usually be sent into the middle of the units and they'll be OK.
9 more stages.