I liked 4.b4, but it doesnt seem you understood the purpose of the move since you follow up with 6.Ng5? The whole idea was to build a pawn center with d4 was it not?
After 6.Ng5 I believe black can play 6...d5 or castle and get a good game. Blacks response was very bad however.
The rest of the game is just a tactical skirmish, computer analysis will probobly be more useful, but overall I think you do well in getting your pieces into play, and making them work together, even though your opononent was very helpfull in getting himeslf into trouble.
Here is a game I played the other night. I won this one pretty handily but when I submitted the game for analysis it appeared to be rife with errors and blunders by myself and my opponent. I didn't go over the variations the engine analysis offered; I merely just observed the percentages of bad moves and etc. Besides it offered a variation at like move 4-5 anyway because it did not agree with me not doing Nxe5. I instead tried a sort of fried liver attack since I learned it the other day and was presented with an oppurtunity to try it out. I'd classify myself as a beginner considering I make bonehead moves a lot and have no idea on how to start analyzing games for myself. I am however committed to improving my game and being able to pass along newly learned skills to my friends who also enjoy chess (but not quite as much as I ;-p) This is the first time I've actually gone through a game and made notes. Any tips, criticism, guidance, advice, verbal thrashing, or anything is welcomed!