Had them both, enjoyed them both ( but both gone now hehe)

Austin Powers is "Poor Man's Monster Bash" - actually we can now call it Poor Man's Iron Man . It's IM's layout with some different toys/features & MB type rules (hit each shot 4 or 5 times, start feature). Good if you want a fan-layout game with flow and humor.

A13 is more like 90's mode based games...and it has LOTS of modes. Cool toys - the rocket & moon magnet are neat. Comes with a shaker installed! 13 Multiball is a gimmick, but a great one - it's always funny.

Both suffer from bad Whitestar sound....but at the same time have music that's true to their licenses. If you like the movie scores, you'll probably like the soundtracks. A13 has Spirit in the Sky which is kinda cool.

At the end of the day, I suppose A13 is the more attractive & interesting game....but AP is pretty fun despite it's art & reputation.