I remember wanting an NGage so bad. I had a whole plan to get my gameboy and all the games together to trade in so I could get one from GameStop. Then I went and actually tried one.
Having to remove the battery to swap out games was too much for me.
It's incomprehensible. I think it came out in 2003. Handheld consoles and their UX were well understood by then. I can't imagine how this device would get greenlit, pass through user testing, and ship. There are so many steps where this product could have been put on hold for revisions. They shipped it regardless. Says a lot about confidence or not listening to feedback.
Having to remove the battery to swap out games was too much for me.