Take basketball, inject it with adrenaline and you get NBA Jam : On fire edition. The core mechanics is basically copied over from the original NBA Jam, like other various ports (College Slam, NBA Hangtime etc.) but it's polished enough to match the current technology standards. So there is no surprise there: 2-on-2 matches, highly exaggerated dunks, the timing of steals/blocks, on-fire bonuses, the weird playable characters... Everything is there with much more increased dynamics which proportionally increases the fun factor.
The game offers various play modes that earn you jam points, which you then spent at the store bying/unlocking stuff. Though it serves as some kind of motivation, the pure joy of playing against a friend outweighs all, whether it's a co-op game or VS one. It's one of those "Holy sh*t it is midnight already" kinda games. Though, the AI routine is pretty much reworked so it's much more human-like, so playing solo is also interesting but it becomes predictable after a while.
Another thing that really contributes is the commentary. Tim Kitzrow's voice plus some of the most hilarious one liners i've heard are absolutely fantastic. He even sings in some rare occasions :) This just speaks more to the effort that is made to preserve the things that are(were) fun from the original and just tweak it a little bit to improve on certain points. Most of the improvements are made in gameplay (various powerups and match modes that favor certain strategy like 3 pointers , assisted dunks etc..) and the effect they achieve is a substantial increase of amusement.
On other hand, this can certainly be viewed as "squezing a buck from already great game" but at least with this one you get the old school sport action in HD. The price is definitely worth it.