Solo independent designer Pixxele of Kakarito Games has released Vault of the Sun: Cycles of Rebellion, an ultra-lightweight sci-fi survival game that strips tabletop play down to immediate tactical choices.
Available digitally via itch.io, the title operates on a lean digital PDF format designed to get players from download to action in under five minutes.
As autumn turns colder and winter weather worsens, days stuck inside become a distinct possibility, making compact games like this ideal to stock up on for quick table sessions. While presented under the banner of roleplaying games, Vault of the Sun: Cycles of Rebellion feels more like a focused tactical challenge, an identity made especially clear by how smoothly and naturally it runs in solo mode.
Core System and Dice Engine

The game operates on a proprietary single-die mechanical engine rather than standard d20 or Powered by the Apocalypse frameworks. All operative actions resolve through a single six-sided die roll interpreted against a strict three-tier outcome table:
- Roll of 6 (Clean Execution): Complete operational success, dealing base weapon damage plus 1 additional damage.
- Roll of 4 to 5 (Strained Success): Partial success, dealing base weapon damage reduced by 1.
- Roll of 1 to 3 (System Malfunction): Severe operational failure, reducing attack damage by 2 and docking the operative 2 Stress points.
Player survival hinges on three core resource pools: Integrity, Stress, and Charge. Depleting Stress to zero leaves an operative incapacitated, facing death after two rounds unless revived by an ally. Reaching zero Integrity triggers a Bleed Out test where a d6 roll determines whether the operative stabilises, revives with half health, or suffers permanent death. Even total demise offers a route forward: rolling 3 or higher on a recovery die shunts the character into the Cybervoid, where fragmented AI entity I.R.I.S. grants 250 credits and reboots them into the City hub.
Setting, Characters, and Operative Roles
Set across the hostile corridors and industrial sectors of the vessel SOLARIS-IV, the overarching story casts players as disconnected fugitives navigating dangerous transit hubs. The setting features five distinct operative profiles, each deployed to a specific sector with fixed resource baselines and dedicated combat traits:
| Operative | Deployment Zone | Integrity | Stress | Charge | Special Trait |
| Atlas | Construction Site | 12 | 09 | 06 | Deals double damage when attacking with melee weapons. |
| Aria | City | 08 | 07 | 08 | Bypasses death rolls at zero Integrity to revive once every four encounters. |
| Violet | City | 10 | 06 | 06 | Secures a permanent 30 credit discount across all equipment purchases. |
| Pierce | Isle of Sgaille | 15 | 06 | 04 | Front-line Apostle resilient in severe combat situations. |
| Kira | Isle of Sgaille | 07 | 09 | 12 | Revives bleeding-out teammates for 50 credits and a Med-Patch. |
Visual Art Style and Layout
Visually, the PDF makes an uncompromising statement through its stark visual design. High-contrast neon typography cuts directly across deep black voids, relying on vivid pinks, sharp purples, and striking hazard yellows. The bold colour choices add character, and the system logs an aggressive, terminal-screen aesthetic that mirrors the raw digital interface of the SOLARIS-IV systems. It eschews decorative page borders or ornate fantasy illustration, instead pairing heavy, outlined poster lettering with raw schematic layouts that keep mechanical readouts completely legible at a glance.
Equipment and Hostiles

Combat encounters measure resource conservation against lethality. Operatives spend hard-won credits at supply terminals to purchase munitions, protective riot gear, and heavy firearms:
- Monoblade: 40 credits, dealing 2 melee damage.
- Laser Machete: 60 credits, dealing 3 melee damage.
- Solaris Pistol: 50 credits, dealing 5 damage at a cost of 1 ammo per shot.
- Wave PDW Sniper: 380 credits, dealing a devastating 8 damage for 3 ammo.
- Supplies: Ammo packs cost 10 credits for 10 rounds, Med-Patches restore 2 Integrity for 50 credits, and Stim-Shots restore 2 Stress for 40 credits.
Opposing the survivors are the Allmother’s automated security ranks. Threats range from minor Royal Maids boasting 1 Integrity and 1 damage output, through to heavy Patrol Duos and elite Royal Guards packing 15 Integrity and crushing 6-damage attacks. Every eliminated foe yields a direct credit bounty, feeding right back into the equipment loop and keeping solo play briskly focused on tactical math.
The zero-prep format stands out as an impressive achievement in accessible game design, requiring nothing beyond the PDF, scratch paper, and a single die to get running immediately.