Halo Wars 2

This achievement can be done in a Solo Firefight match or an online game with other players.

Amassing a score of 5,000,000 points may seem daunting, but once you clear the first Boss wave (wave 5), be it alone or with other players, you should have little trouble steadily collecting resources and building a strong army to fend off against the Flood. The basics of Terminus Firefight apply here: wipe out the enemy forces and complete each wave without too many friendly causalities. Additionally, you and your teammates should focus on capturing some of the mini-bases around the perimeter of the map because the more mini-bases you hold and the quicker you finish each wave, the greater the score multiplier will be.

As for scenario planning and/or strategies, there is no one way to play. That begin said, however, it's entirely recommended to focus on stockpiling resources (via Supply Pads/Harvesters and Generators/Power Extractors) for the first five waves and using only standard Infantry Units to defend the Terminus. Past wave 5, you should focus on stronger, more formidable units such as Hornets/Banshees, Scorpions/Wraiths, and Hero Units. When resources allow, upgrade your main HQ to unlock next-tier upgrades and then work on unlocking those upgrades. The stronger your units, the easier it is to defend the objective.

If playing with others, each pathway that leads to the Terminus can be covered by a single player; if playing solo, however, you will have to be quick to cover both chokepoints with your army. Finally, as a few extra tips, be sure to keep these strategies in mind:

• Build Barricades! Fences and Shield Barriers are a big help in delaying the enemy from reaching the Terminus. Don't forget you can upgrade Barricades twice, depending on the type. If you are playing as a UNSC leader, Reinforced Bunkers are very helpful since Marines can be position inside.
• Venture into the unknown and secure at least one mini-base per side of the map. Once the mini-base is secured, you can build several Turrets. These bases will act as a "first line of defense" when the enemy spawns into the map, allowing you time to either move your Units towards their position, or build/upgrade back at the main HQ.
• Aerial Units. Build them. Upgrade them. They are extremely agile, cost effective, and deal a great amount of damage when upgraded.

With a strong defense holding down the Terminus, you should be able to reach the required score by wave 45-50 if playing alone, or wave 25-30 if playing cooperatively. Either way, while working on these score-based achievements, you will unlock "Garrison," "Barricade," and "Fortress" for completing waves 10, 20, and 30, respectively.

Once you have reached an individual score of 500,000, "Terminus Tactician" will unlock. "Terminus Teamwork" and "Terminus MVPs" will not unlock until after the match has ended, whether that be via mission failure (the Terminus being destroyed) or completing wave 100 (which is the final wave).

NOTE: If you are playing alone, make sure to change the difficulty to Easy (you cannot change the difficulty when playing cooperatively).