Comrade, I have always said Tonma was a poor man's Karnov. This is a compliment, since Karnov is a rough diamond that never got the love it deserved.
Karnov is far more creative (the item/weapons system is implemented well and CLOSELY interwoven with stage design and progression, IMHO), but if you strip that out, you end up with Hero Tonma.
I' m too lazy to rehash my own garbage, so I may link to an old post.