I played Jak 2 when it first came out and I definitely didn't like it at first. The game seemed so different from the first iteration and so I was immediately turned off by it. However, still being a kid and only getting to handful of games in a year, I forced myself to keep playing. Thankfully I did because I definitely enjoyed the game a lot. But I don't remember how long it took me to like it. I don't remember if I still hated the game 5 hours in like you.