NOTE: The video depicts a successful run of "Gazer Guard's" first phase, so some of the interactions described in the following paragraph aren't seen here. Valfaris expects the player to risk death during experimentation, so defeating this boss for the first time may take multiple restarts, refining and hastening the eventual successful run.
The majority of enemies in Valfaris take direct damage from weapon fire, but "Gazer Guard" does not, setting up a unique boss fight. When "Therion" fires upon the central eyeball which appears to be the boss's body, its blue shield aura* and static health bar indicate that damage is not being inflicted. This feedback is identical regardless of "Therion's" equipped weapon, ruling out direct attack and suggesting a more patient approach. While the eye remains invulnerable, six floating beacons dash around the screen, pause, and repeat in an ostensibly randomized pattern. "Therion" cannot interact with the beacons while they are moving; though they can be attacked during the final and longest pause. Attacking a beacon won't kill or damage it, rather it triggers one of two events. When a beacon is struck, the boss eye either fires a single aimed laser directly at "Therion", or it recoils and its health bar decreases by a fixed decrement. Afterwards, the beacons resume their pattern of shuffling and the eyeball remains invulnerable to direct attack.
The first test for the player is reading the scenario as laid out. Once they've experimented enough to determine that the beacons are vulnerable and not the eye**, they need to figure out why sometimes damaging a beacon hurts the boss and other times it triggers a counterattack. They may deduce that given six beacons, only one is a correct target, or they may simply continue observing and experimenting until they come to the same conclusion. This should draw their attention to the shuffle, at which point they need to observe that one and only one beacon glows blue at the beginning of each cycle, just before the shuffle. At this point, the player has passed the reading/observation test; their reward is the knowledge of which beacon to target.
Now the focus shifts to the shuffling pattern. The target beacon is indicated before the shuffle, but the vulnerability window comes after. The player needs to track the (now identical) target beacon as the pattern speedily and repeatedly reconfigures. It's a game of three-card monty, a fairly rudimentary and likely familiar test of vision. This is the second test; the reward for successfully tracking the beacon through the shuffle is again knowledge, this time knowledge of the target location when it becomes vulnerable.
The third test barely registers as such, it should be so ingrained into the player at this point. As the beacons finish shuffling and are fixed in place, they lose their purple glow, indicating a change in state that experimentation will have revealed to be their vulnerability window. If the player has passed the first two tests, they know now which beacon to target and where it is. If any other beacon is attacked at this point, the window ends, the eyeball attacks, and the cycle restarts. Striking the target beacon without damaging any of the others is the third test. This can be accomplished with a melee weapon by running and jumping to its location, or with a ranged weapon by aligning "Therion" with his target along one of his eight axes of aiming. This action needs to be accomplished in a short period of time (1-2 seconds), otherwise the cycle restarts. To pass the test the player needs to be able to quickly attack an arbitrarily placed element (the target beacon) while aiming around its cover (the other beacons). This time the reward is damage to "Gazer Guard" - irrevocable progress in the boss fight.
This ends the suspension of challenge and the cycle of tests returns to the beginning. Invoking the rule of threes, the player needs to complete this three-part test three times to end phase one of the battle. The beacon movement during the shuffle becomes faster through progressive cycles, increasing the difficulty of the middle test while leaving the other two consistent. This produces a linear difficulty curve. Phase two will be discussed in the next video.
What makes this part of the "Gazer Guard" battle particularly elegant is the inverse relationship of complexity and suspension as the tests progress. The first test is highly specific to this boss and requires processing and filtering novel information. The subsequent shuffle challenge is a new way of testing visual tracking, a skill underpinning the entire game. The player is applying a developed skill to a novel scenario, which they ought to be more comfortable with than they were with the initial analysis. At the peak of suspension, the third test, the player needs to aim and shoot at a static target, something they've been doing against every enemy in the game. As more successes are suspended on the line, the abilities tested are increasingly fundamental - this gives the game cohesion and identity: victory in Valfaris is ultimately determined by running and gunning skills, not isolated puzzle solutions.
* the blue shield aura is an indicator the player should have learned by this point in the game, as it is used on every enemy that receives an attack but no damage (guarding).
** you could say experimentation is the first test, but I think that's implicit in any scenario where the player does not yet know how to progress.
