Welcome to the site and thanks for the feedback yesterday! I really appreciate your input and I'm glad you like the site so far. I think both of the features you requested are great ideas and in fact, I've already implemented one of them :)

If you go to Game Search (i.e. Browse Games) page, you should now have a Quick Add option available to you. For now, you can only enter a subset of the fields on a game, but I can add more later. I basically re-used the existing Quick Edit feature, so I was able to wire this all up pretty quickly.

Let me know what you think and if you have any additional feedback on it. Like I said, I can add more fields, so if you'd like to see some more in there, just let me know!

Oh and I haven't forgotten about the other feature you requested around achievements, it's been logged onto my task list!