when I first saw this previewed in Nintendo Power in 2008 I thought it was about Mario and Luigi entering Bowser's body to systematically shut down each of his bodily systems until he died from total organ failure. Given that I assumed that to be the premise it's kinda concerning I was so eager to play it
Mario & Luigi: Bowser's Inside Story is the peak and pinnacle of the series. Both the bros and Bowser have fun to use move-sets, with Mario & Luigi having their returning attacks polished. The game combines 3D puzzles via the overworld with 2D puzzles in Bowser's body, allowing for the best of both worlds. There is also a good bit of side content, with some satisfying rewards alongside them. The story is pretty good as well, particularly in the character department. Bowser is good fun as always and his humor is great. Fawful is possibly one of the best villains in the Mario series, his personality being a breath of fresh air from the somewhat generic maniacal villain stereotype that Cackletta and Princess Shroob had. Overall, a very good turn-based RPG.