In action games, a boss is not just an enemy with a huge health bar. It’s a final exam for the player. After winning, the player should feel catharsis and strong positive эмоtions.
In GRIMPS, we treat boss fights as a checkpoint that tests three key things:
- Mastery of mechanics. How well the player uses the tools learned throughout the game.
- Reaction and timing. The ability to read animations and react within tight windows that give an advantage in combat.
- Resource management. Control of positioning, stamina, and cooldowns of both the player character and the companion.
- Boss design in GRIMPS stands on three pillars, all working together to create pressure:
- Visual and narrative language. The boss’s silhouette, visual design, and animations must instantly read as a higher-level threat than a regular mob. The player should never wonder who they are facing.
- Animations and timing. All attacks must have clear visual and audio tells, but the reaction window is intentionally tight to keep constant tension.
- Sound design. Sound is not just atmosphere or epic flair - it’s a gameplay trigger. It marks the start and end of dangerous phases and reinforces the feeling of pressure.
Boss Example: Arena Control Through Phases
Let’s look at how this approach works using one of our bosses.
This boss is a large unit whose main goal is total arena control through phase changes. Each phase teaches the player a specific behavior, then breaks the learned pattern.
In the first phase, the boss acts like an artillery unit. It launches large fire spheres - projectiles that explode on contact with the ground and leave active pools.
- Pool mechanic. Standing in a pool applies slow and damage over time. This is classic zoning: the arena is temporarily divided into safe and dangerous zones, forcing the player to constantly decide where to move.
- Impulse explosion. When the pigeon breaks the boss’s shield, an area-wide impulse explosion is triggered and a damage window opens, allowing the player to deal massive damage.
This mechanic serves two purposes:
It rewards correct timing.
It teaches that dodging is not only horizontal movement. To avoid the blast wave, the player must crouch, introducing vertical timing into the core movement set.
The second phase starts once the player has learned the first phase. When the boss drops to 50% health, it enters berserk mode and the fight speed increases sharply.
- Projectile changes. Fire spheres are no longer launched one by one, but in volleys. The player can’t rely on “one projectile - one jump” anymore. They must either predict the whole series or use cover.
- Added obstacles. In addition to the shield, the boss starts generating fire waves across the arena floor. This forces rhythmic jump-based gameplay: the player must constantly jump over obstacles while also dodging projectile volleys.
- Finisher. At the end of the phase, the boss triggers a large area explosion. This marker attack signals a phase transition or the end of a cycle. The player must track the timer and plan an escape in advance, not just react at the last second.
This boss does not exist in isolation. It is a marker - a checkpoint that tests how well the player has learned the mechanics introduced earlier.
- Barrier-breaking check. Earlier, the player encountered tanky enemies with barrier shields and learned that the pigeon is used to break shields.
The boss reinforces this skill but adds a condition: the shield must now be broken at the correct timing, under heavy pressure.
- Movement check. Flying enemies with projectiles taught the player to dodge spheres and avoid pools.
The boss takes this pattern and scales it up, forcing the player to dodge projectile volleys in limited space.
Beyond skill testing, the boss also serves a narrative purpose - it reinforces the “player + companion” bond. By this point, the player might see the pigeon as just another damage tool. This fight is designed to break that perception: without the pigeon’s dash, the boss’s shield cannot be broken.
Visually and mechanically, this reads as a moment where the companion saves the player in a situation that cannot be solved alone (or is extremely difficult). This shifts the relationship from “bonus damage” to “condition for survival.” You can already see how this boss works in action in the GRIMPS demo:
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