Nintendo

After the Main Story there is the option of an endless mode, but i haven't reached it yet. A lot of it happens to be experimenting with components to find cooking recipes, which give you different kinds of Food, varying in healing amount and speed of healing or effects like "Coyote Time" (the effect of Wile E. Coyote, the nemesis of Road Runner, being able to walk in the air for some time); some recipes give you trinkets to equip like an "extra lung" for longer breath underwater, or some grenades.

There isn't much meta-progression outside of expanding your stash, leveling your weapons and being able to start in every area you have reached before. There is one Stash where you can send equipment down the toilet, an option to buy ammo cheaper in bulk and some benches that give you the ability to remove oils and enchantments if you decide that what you created is not viable for combat lol.

Weapons gain XP, which gives you slots for oils and max. 1 Enchantment - but the more you put on your weapon, the faster it degrades, which gives a nice balance, because you will probably not be able to use your Uber-Gun for everything.

The levels themselves use premade rooms (so they are not random generated crap), but the placement of enemies, ledges, loot and secrets is randomized (There is always only max. 1 secret room per level, so if you found it already, you can stop searching for it, but there might be more hidden loot boxes throughout the level).