There was a lot wrong with it, and it's been pulled apart by much smarter people than I, so I'll talk about the two things I enjoyed about it. Ben Kinsley as the Hood was great. A lesser actor would likely have chewed the scenery a hell of a lot more, while he played it with a good amount of menace. I found myself really enjoying his performance.
The other element was the characterisations of Lady Penelope and Parker. A very enjoyable teaming, with some beautiful interactions between the pair. Again, almost every time they were on screen was wonderful.
Unfortunately their fight scenes were marred by comedic sound effects of the "boing" and "bonk" variety. Whoever thought that would be a good idea should be shot, along with every level of production above them that let it go through.
Needless to say, I would have much preferred a true Thunderbirds films, maybe one with the team dealing with a series of disasters engineered by the Hood leading to a trap or showdown of some description. But hey, I care about the original.
Scary to think that Parker and Stone, the creators of South Park, may have actually treated the material with more respect. Oh well, that's Hollywood.