It took 126 jumps but I beat both bosses. I have to say I'm really impressed.
The graphics are a nice switch-up from the last game. The ground looks much better, and while that's the only major change, it counts. I wish it were a little more blurred or more detailed, though. As it is, I can see strange blurred textures with razor sharp edges running across, as if you have a texture that doesn't loop well. The buttons, tricks, and new graphics (such as the rockets and dumpster) look very good and for what this game is I wouldn't ask for anything more.
The sound effects are kind of basic and I wish you had more variety, perhaps with voice acting as well. You could probably make a really funny plotline to a game like this, it's too bad it's not really expanded on. I'm glad there's no music, as I spent a long time playing this and would have gotten sick of anything you put in.
The gameplay is definitely improved from the last game. The upgrades are simple and effective, though I'm really not a fan of all of the new tricks since it became hard to remember some of them. Overall I liked the whole risk-reward thing with the groupies, and it was satisfying building my way up. The one problem I would note is that between having all of the equipment and upgrading to the dumpster, earning the money for it takes far too long and ends up being a very protracted part of the game, especially in contrast with how cheap Dumpster Dive is immediately afterward. The same can be said for the golden cart and Hang Glider.
The main reason I really like this game, though, is that you incorporated those two boss battles. While I felt they were both way too difficult, I also liked that they broke up the gameplay and offered a stunning level of variety. My only gripe here is that you can only fight each boss once. I wish there were options that would have allowed players to pull off a bunch of tricks, fight a boss, and then stick a really cool landing all in one go - maybe even allow the player to fight both bosses in the same run. The 2000 point bonus is also pretty measly considering the difficulty of the bosses, I think a x2 multiplier would be more appropriate.
Overall I like the added replay value and updated features, but something should be done to improve end-game replay value. Perhaps certain challenges that isolate height, distance, and style, or more challenges involving specific upgrades or bosses (eg. go X meters only using the single booster).