Mechabellum is an army-planning game where your units do the fighting after you decide where they go. Star Expedition turns that idea into a two-player online expedition: each commander fields an independent force, both armies share one battlefield, and the pair works together to defeat a succession of enemy lineups. You are not taking turns controlling a hero through a campaign map. The teamwork happens in the planning: deciding which units to field, where to put them, what to upgrade, and how much to commit to the next fight.
That makes Star Expedition a more deliberate kind of co-op than a shooter or action game. You can talk through a plan while the battle is waiting for deployment, then watch it resolve without needing quick hands. The mode has no countdown on the planning phase, so a pair can take time to compare options. If you want a familiar human opponent to outthink, the regular versus modes are still there, but Star Expedition is the clearest fit for two friends who want to face a shared enemy together.
Two commanders, one battlefield
Each player controls their own army. The forces meet on the same field against a single opposing lineup, so you and your friend are solving one combined tactical problem while making separate unit choices. You do not share a pool of troops or hand direct control of your mechs to the other person. Instead, compare what each half of your force can cover: one army might hold a difficult lane while the other brings the units or upgrades needed to break through another part of the enemy formation.
A round begins with decisions rather than movement. You spend resources on units, position them on the grid, and choose technologies or other options as they become available. Once the deployment is set, combat plays out automatically. Your mechs select targets and attack according to their abilities and positions; you watch to see whether the plan worked, then adjust before the next deployment. A tank in the wrong place, a thin front line, or a missed counter can matter more than how quickly either commander clicks.
The setup rewards conversation. One player can call attention to a dangerous enemy unit or a gap in the front while the other considers a counter. You can split attention between different parts of the board, but both commanders still need a sense of the whole formation: concentrated force can overwhelm a point, while a broad line can stop smaller units from slipping through. There are no fixed character classes that assign one friend to support and one to damage. Each commander chooses from the same kind of tactical toolbox and finds a useful contribution in the current matchup.
A run across nine planets
Star Expedition gives those battles a longer shape. A run sends you across nine planets, with each stop presenting a new challenge built from changing units, technologies, reinforcements, and an army layout drawn from another player’s battle. These are not live human opponents reacting to your choices in the moment. They are recorded army builds you must read and counter together. The result keeps the familiar prediction-and-counterplay of Mechabellum while removing the pressure to match a live player’s timing.
The sequence feels closer to a tactical puzzle run than a scripted story campaign. You build a force from the options the expedition offers, test it against the next formation, and carry rewards forward to influence later attempts. One run may steer you toward a useful unit combination you would not normally choose; another may leave you wishing for a particular counter that never appears at the right moment. That uncertainty is part of the mode’s appeal, but it also means two friends looking for a fixed, authored mission list may find the structure less satisfying.
Your choices happen at two scales. Before a run, a loadout gives you a starting emphasis; during the expedition, the unit and technology options shape how that plan changes. Once an army is on the field, placement and timing are still yours to decide, but the fight is automatic. The combination makes small adjustments matter. A sturdy unit can buy time for a damage dealer, a fast group can reach vulnerable targets, and an upgrade can turn a familiar unit into a better answer to the formation in front of you. These are tactical examples, not assigned roles: what works depends on the lineup and the choices offered in that run.
The lack of a round timer makes this mode more conversational than standard versus. You can pause over the deployment, compare possible purchases, or take a moment to understand why the last fight went badly.
The rest of the game is more competitive
Mechabellum also has regular 1v1 and 2v2 battles, free-for-all, and Survival against waves of computer-controlled enemies. In 2v2, two players team up against another pair of human opponents. That competitive team mode is distinct from Star Expedition, where two commanders cooperate against shared enemy armies.
Survival offers another PvE alternative, pitting a team against waves instead of another player’s recorded army build. That is the more straightforward choice if your group mainly wants to see how long its defenses can hold. Free-for-all is a contest among human players, and the standard ranked game is built around reading and countering a current live opponent. The menu contains several modes with different rhythms, so make sure you are selecting the shared-enemy option if that is what you want from a co-op night.
Strategy is the draw, and the learning curve is the cost
The units are visually distinct, and the battlefield gives you a clear before-and-after: choose a formation, watch it collide with the enemy, and look for the reason it held or broke. That readable cause and effect is satisfying when a counter lands. A swarm can occupy or overwhelm targets while heavier machines trade blows with the front line; ranged units and specialist technologies can change which threats deserve attention. The sheer variety makes a small deployment screen carry a lot of tactical possibility.
That variety also creates a learning load. You need to recognize what different units do, which technologies change their behavior, and how positioning affects target choice. Mechabellum includes tutorials and practice options, but the opening menus and size of the unit roster can feel busy to a new commander. Pairing up helps because two people can reason through options aloud, yet it can also turn a simple deployment into a longer discussion. If both friends are completely new, expect the first few sessions to be about learning the vocabulary as much as winning fights.
Star Expedition adds a further source of swing: the enemy army is drawn from real player builds, while your own run offers changing units and upgrades. One encounter can feel like a clean puzzle; another can present a much harder formation or a counter that is not in your current shop. If your group prefers a carefully staged difficulty curve or wants to repeat the same encounter until it is mastered, this less predictable run structure may grate.
The battle itself provides spectacle, with missiles, beams, impacts, and large mechs moving across a wide arena. The camera lets you follow the collision rather than steering an individual unit. During a dense round, overlapping effects and many unit types can make the field visually busy, and the important information lives partly in small deployment and upgrade panels around it. Strategy-first players may enjoy reading those details; anyone hoping for a cockpit view or direct real-time control will find a very different game.
Group size, platforms, and online setup
Star Expedition is an online co-op mode for two players. It is a compact format for one friend rather than a way to bring a larger group into the same PvE run. If you have three or four people, choose a mode intended for that size, such as free-for-all, or rotate commanders between expeditions. The separate 2v2 mode allows four people to play on two opposing teams, but it is competitive rather than cooperative PvE.
The game is available for Windows and macOS. For Windows, use Windows 10 or later as the practical Steam baseline; the product requirements still show Windows 8 as a minimum, while the Steam client itself requires Windows 10 or newer. The Mac build lists macOS 14.5 and an Apple M1 as minimums. Linux is not listed as a supported build. Mechabellum is a sequence of online matches, not a persistent world or shared survival server.
Is Mechabellum a fit for your group?
Star Expedition suits friends who like comparing plans and adjusting a shared strategy, but want enough time to think between fights. Its no-countdown planning and automated combat make it accessible to players who do not enjoy fast clicking. The two-army battlefield gives both friends a real stake in the same result, and the changing expedition choices can nudge you away from familiar openings.
It is a weaker fit for a group that wants a story campaign, persistent base-building, direct character control, or an easygoing action game. Your shared objective is to defeat each opposing army, not to complete a handcrafted narrative mission. A broad unit roster, randomized choices, and varying enemy layouts can make learning exciting or frustrating depending on how much uncertainty your pair likes.
Choose Star Expedition when two friends want co-op PvE with room to discuss each deployment and adapt across a run. Choose 2v2 when you want to test your teamwork against another human pair. Either way, Mechabellum asks the group to enjoy planning and watching the consequences more than commanding units moment by moment.