The control loop
Hook or scare a creature out of the water, inspect it, then decide whether to kill it by hand, knife, brass knuckles, pistol, rifle, dynamite or grill. Airborne kills can stack style multipliers such as headshot, no-scope, 360 and one-shot.
Cooking timing
Hold the fish over the grill and watch the value climb. Pull it before it burns; cooked fish is also a healing resource for the later Boss fights. Use F to inspect the item state instead of guessing from the color alone.
Co-op input checklist
Before a four-player run, have every player join the same session type, confirm their controller glyphs and test the revive interaction. Patch 1.0.5 added private lobbies and in-game session type changes, so a public/private mismatch can look like a broken input.