That's very unfortunate, because after the first world is where things start to pick up in Jungle Climber. The challenges get more creative, some of the better songs appear, the environments diversify, and it all leads up to the epic final boss battle. If you still have the game lying around, I would really recommend at least playing through the second world. As for King of Swing, you're not really missing much. It's pretty easy all-throughout and it's entirely skippable, but that won't stop me from giving it credit as a good two hour pastime.
As for Barrel Blast, the best thing I can compare it to is Smash coincidentally. Trying to play Barrel Blast like Mario Kart is like playing a Smash game for the first time as a kid and only using specials. You're missing half of the depth to the game. I find it fast-paced and aggressive because, during a race, you should be hitting, dodging, strategizing, and competing for advantages and the finish line. You want to do more than just pass your opponents; you want to cripple them and Barrel Blast gives you more tools to do that than a more casual racing game.