God of War Ragnarok gives you plenty of tools to take down the various threats you'll face across the Nine Realms. Kratos has his trusty Leviathan Axe and his Chaos Blades, with Atreus chipping in with his bow and arrow. There are plenty of other ways to tear your enemies apart on top of that too, but all YouTuber ColossalKiwi needed for their most recent run is Kratos' shield, as they pain stakingly made their way through Ragnarok only using L1 attacks.
ColossalKiwi uploaded their entire attempt to YouTube, in which they only allow themselves to fight enemies with their shield, apart from during several unavoidable quick time events in boss fights. They also use the Leviathan Axe and Chaos Blades to get through many of the game's puzzles, but as far as combat goes, it's shield up at all times. As you probably expect, there's pretty heavy spoilers for God of War Ragnarok from this point forward.
Most of CollosalKiwi's issues during this run arose during the game's many boss fights, the first being Bjorn in the opening few hours. To demonstrate how to use Spartan Rage, the game locks you into it until you start dealing damage. Since ColossalKiwi is only using a shield to fight, that's pretty much a no go. Thankfully, they manage to waste their Spartan Rage by throwing a boulder at nothing, so on the run continued.
There were other, slightly more questionable issues with the run, especially during the part where Kratos' shield breaks and he's left slapping enemies instead of striking them with a shield. There's a few issues with some other bosses like Nidhogg and Heimdall, but ColossalKiwi does eventually complete the game with just a shield, barring a handful of wisps that can only be damaged once you've fired a Runic Arrow at them. It's still an impressive accomplishment everything considered, and might be something you want to try next time you go to boot up Ragnarok.