Just as a bit of a counter to all the Isaac love (and, don't get me wrong, I love Isaac):

BoI is probably the best roguelite... from the early 2010s. The gameplay is ridiculously solid but the upgrade design and drop system has too much in common with the roguelikes of old where you would often lose a run because the purple potion was instant death on this run.

There are just so many upgrades and synergies that you might become completely unkillable on floor 2 of one run and then have your entire build ruined on floor 5 of a different run. I STRONGLY encourage playing with the wiki or https://tboi.com/ open on a second device/display to avoid these run ruining pickups because you happened to forget what THAT weird egg looking thing did with a different weird looking egg thing.

On PC there are mods that integrate this into the game (and I think you can use it with achievements after your first matricide?). And I think Edmund has said he wants to add that to the base game sooner than later?

But contrast that with games like Hades where basically every single upgrade is a pure upgrade and you have good item descriptions before you pick anything up (so it is mostly a case of deciding what damage types you want to spec for). Or Dead Cells where you can easily swap out a weapon if you decide you didn't like it. But in Isaac? You are basically chugging mystery potions on every floor.