It's clear within minutes of starting the game that Edmund McMillen
was not expecting this game to be the runaway success it was. You play as a small pink boy who stumbles through floors reminiscent of The Legend of Zelda
while flinging tears at a variety of odd enemies, with the help of various power-ups (most of which physically mutilate you), pills which have as much chance of permanently lowering your stats as they do increasing them, and a variety of tools, familiars, and bizarre religious imagery
up the wazoo. And yet, it works.
The layout of the game is randomized, with each floor (for a while anyway) having a shop, a treasure room, a boss, and truckloads of enemies in between. It would probably be quite a standard game if it wasn't for the items. There are the usual suspects; bombs, keys, a map... and then you find your first treasure and all hell breaks loose. Your tears can be replaced with explosive bombs you vomit on enemies. You can cut your head off and fly around while your body follows as an assistant. You're even occasionally given the chance to trade your health for powerful upgrades which can result in a demonic Isaac flying around and spewing a screen-wide stream of blood on enemies. A lot of the best items are unlocked the more you play, but it keeps you coming back.
That's not to say the game is flawless. While most of the unlockable characters have their strengths and weaknesses, Samson just sucks. Plus, at its core, the game can sometimes be overly dependent on luck - sometimes you can make it quite far before you get the sinking feeling that you have almost no health, a basic attack, no speed, and you just didn't get any useful power-ups
. When that happens, it definitely feels more than a little unfair.
All in all though, it's a very replayable game, and I can't imagine any player not feeling satisfied when they find one of those glorious combinations that turns Isaac from a helpless weeping boy into a winged and horned laser firing monster with the power to decimate everything on-screen in seconds. It's unfair, confusing, sometimes impossible, and genuinely filled with the exact kind of creative passion that makes independently-developed games that most exciting and original in the industry.