Something about this stuck a chord with me, so I decided to comb the video and check when the player has access to direct input with the game. I define direct input as when a player can press a button and make something happen on screen (i.e. whether it be just moving forward, pressing triangle to open a door, or shooting a rebel in the face).
(O:46-1:45) 59 seconds of play gameplay = Player controls climbing/rappelling down the zeppelin with a minor second or two of conversation, until Galahad reaches the bottom. I can't quite tell if the player has any interaction to climb towards the door, so I left it off.
(3:25-6:00) 2 minutes, 45 seconds with ~ 10 seconds loss of player control = Player has direct control over Galahad now with movement, there's a few minor seconds where the NPCs talk in front of a door (still have complete control), and a few seconds where you lose control before going into stealth mode. Then there's the Inverter/Rectified minigame, a quick few seconds cut away to show a guard getting suspicious, before going back into sneak mode.
(6:15-8:23) 2 minutes, 8 seconds = beginning of stealth sections with a stealth kill to a guard, and moving towards a door (that you get to open!

) and a quick cutscene happens after opening the door
(8:35-8:58) 23 seconds = move forward
Subjective part Depending on how you view interactive cutscenes, this upcoming descriptions may or not be "gameplay" to you. To me, whenever a player has the ability to press a button to interact with the game that relates directly into action, that's gameplay, especially if your failure to interact correctly results in a loss. If what I describe isn't gameplay to you, then so be it. I won't argue with you.
(9:09-9:14) 5 seconds = count down to grenade throw, pull the pin, throw grenade
(9:25-9:26) 1 second = player failure to hit QTE
(9:40-10:00) 20 seconds = player QTEs, with interactive camera that you can pan over to items to hit the guards with (in this case, a fire extinguisher)
End subjective part
(10:30-11:32) 1 minute, 2 seconds = move forward into stealth section #2, total control over movement with stealth kill
(11:33-13:44) 2 minutes, 11 seconds = lockpicking minigame
(13:45-16:25) 2 minutes, 40 seconds= player control, open door yourself, into stealth section #3 (with hilarious lockpicking bug), open door yourself at the end
(18:25-20:25) 2 minutes = the sniping marking minigame, marking the rebel guards, ending in player failure for taking out the wrong guard first
(20:40-21:00) 20 seconds = player shoots the right guard
(21:25-24:45) 3 minutes, 20 seconds = third person shooter section #1
(25:04-26:25) 1 minute, 21 seconds = third person shooter section #2 ending with going down a ladder
(26:38-26:58) 20 seconds = player movement
(28:45-28:46) 1 second = press triangle to pay re-er, drop a lifeboat
(28:58-32:46) 3 minutes, 48 seconds = player movement to another Inverter/Rectifier minigame, another door you get to open yourself, there seems like there's a jump cut here of the player grabbing ammo and guns, then there's the
one door a NPC opens for you during gameplay, another door the player opens themselves, and checks a corpse. There's a minor 2 second cutaway while the ship shakes. Player body checks open a door and moves into third person shooter section #3 which results in a death.
(32:51-35:28) 2 minutes, 37 seconds = attempt #2 on section #3, ending at Galahad getting separated from his comrade.
So, in this 36:17 video, we get 26:21 worth of gameplay. That's almost a 3:4 ratio of "gameplay:cutscene" or "player control:not player control".
I really am that bored at work