Overrun! offers a detailed simulation of squad-level action in European and Middle Eastern terrain during late twentieth-century conflicts. Players command a battalion of infantry, armor, artillery, and helicopters on behalf of various countries, including Arab states, Iran, Israel, NATO, and the Warsaw Pact. The scenarios are mostly speculative and focus on near-future events, with one historic war presented as part of the game.
SSI builds on its Panzer Strike engine with this release. Each unit has several static attributes, such as size and morale, which affect combat effectiveness in real-time based on orders and circumstances. The game features dozens of detailed weapons, each with six characteristics. Vehicle armor is also distinguished by location, making facing a crucial factor in combat. The currency of each turn is orders, gained and spent by command units. Without orders, squads will continue their actions or react to external events. If a squad loses its commanding superior, control passes to the computer. Orders are issued almost in real-time due to continuous movement and action in 20-second pulses.
The game's play screen features a small-scale map with a limited level of zoom, requiring scrolling to judge terrain conditions. A line-of-sight tool helps reduce guesswork. Below the map is a menu of abbreviated commands and submenus, along with a status line for selected units or terrain. Terrain factors can be modified in-game through smoke effects.
Scenarios can be played solo, head-to-head with two players, or entirely by the computer. A scenario editor allows complete control over map creation, initial forces, and various engagement types, objectives, and difficulty levels.
