It's absolutely ahead of it's time and just altogether brilliant.
The world is vast and incredibly dense and detailed. There are secrets galore. You are tasked by your master to find the eleven rings of power, which most people believe to be just legends, and return them to your God before the Evil Void finds them. You are free to complete your quests in any order you choose.
It's the little touches that make the game, like different NPCs holding different beliefs about Nexus and Void. Some love them, some hate them, some doubt their existence. Vagrants will chant nonsense code at you. Keef the Thief makes an appearance. You can meet a talking bear that lives in a house in the woods, fight zombies underwater, meet RedBeard the pirate, trade goods, and gamble at the casino. There's so much to do in this game.
Sure, the graphics aren't top-notch. Sure, the music can be brash. Sure, Buc's walking animation is as far from "smooth" as you can get. But I simply don't care. If you're able to look past that, and the initial difficulty, there's a brilliant and deep experience to be had here. A phenomenal, engrossing, strange, comical, and wonderful adventure. There is nothing else like this on the Genesis.