It's inarguable that God of War is an important game, but is it still fun to play? No, not really, but it has its moments. It came late in the PS2 lifecycle and took inspiration from character action games like Devil May Cry, but it added a sense of brutality that launched a fleet of clones.
The problem is, the God of War you remember didn't start wtih the first game. No, it became the setpiece-heavy boss-a-thon with God of War II. The original features far more hallways, and almost no bosses, but lays down a solid technical framework for what would come.