Unlike the developer's previous effort, this game takes place in a more modern setting, albeit one with giant mechs. The game is directed by George Kamitani, with the music composed by members of Basiscape.
13 Sentinels: Aegis Rim contains examples of:
- The '80s: The game is set in a fictionalized version of 1980s.
- Art Shift: A first for a Vanillaware title. The Real-Time Strategy segments are displayed on a holographic radar with 3D graphics instead of the usual hand drawn sprites.
- Ensemble Cast: The game features a total of 13 protagonists, each with their own intersecting storyline.
- Heal Thyself: You can order your pilots to perform field repairs to keep their Sentinels in fighting shape. This leaves them highly vulnerable to attack, however, so you will need to keep an eye on your enemies to avoid being attacked while defenseless.
- Humongous Mecha: A pivotal part of the game as the protagonists fight in these, called "Sentinels".
- Ordinary High-School Student: Most of the cast are normal high school students.
- Scenery Porn: The game features stunning backgrounds, which is hardly a surprise, given this is developed by Vanilla Ware.
- Technology Marches On: Invoked. The different classes of Sentinels are based on advances to the technology they are built on, with different generations of Sentinels having different capabilities:
- First-generation Sentinels are melee-focused bruisers that focus on destroying enemies in close quarters.
- Second-generation Sentinels have more balanced capabilities, being able to engage enemies at various ranges, as well as summon support units.
- Third-generation Sentinels are outfitted with powerful long-range weapons, from missiles to railguns, allowing them to destroy enemies across vast distances.
- Fourth-generation Sentinels benefit from being able to fly, using superior mobility to provide support to allies.
- Tower Defense: The RTS portions of the game center around commanding a team of Sentinels to protect a Terminal. If the Terminal falls, it's Game Over.
- Time Travel: While most of the main cast hail from the present era, some hail from a Bad Future, and others from World War II, all come together to deal with a mutual threat.