Kremling Kosh was fine, it's just a bit challenging to get the required hits in time, and you only have a few seconds to blast them. Red Kremlings or tough, but they do net you two points each.
Batty Barrel Bandit was easy, you just have to time your stops on the wheels.
Beaver Bother was the most annoying bonus stage of all. I can handle the one in Frantic Factory with Diddy Kong, but the two in Creepy Castle? Give me a break. Getting 15 is tough in 60 seconds. Not to mention you're as Klaptrap to lure the beavers into the pit.
The Mine Carts were fun, I enjoyed playing them. There were only three of them, and in the same stages as the other topic, but different characters. After completing them, it's a shame you can't play them anymore.
Stealthy Snoop were another of my favorites, as well. Only Donkey Kong and Diddy Kong for this one. Navigating the maze was fun, and I liked the music there. But I didn't like how there were only two of them in the whole game, one in Angry Aztec and the other in Gloomy Galleon. Worse, you can't play them anymore after you beat them.
Peril Path Panic was another easy one, you just have to shoot the Klaptraps to prevent them from eating the Banana Fairies.
Big Bug Bash is easy as well, but I hate how I waste time when I try to squat the bug and it misses. I hate the bug's taunts.
Searchlight Seek is easy, I just hate it if the Klaptrap moves away and avoids the watermelon just out of reach, taking precious time.
Splish Splash Salvage is sometimes annoying with the underwater controls, but it's otherwise easy. Getting the coins in the barrel are easy, but a few of them are not touching the side of the barrel.
Speedy Swing Sortie is nothing but a cakewalk, swinging from vine to vine is fun.
Mad Maze Maul is kind of fun, defeating the baddies in the maze.
Mine Cart Mayhem are my favorites. Chunky in Jungle Japes was the easiest one, proved no challenge. Donkey Kong in Fungi Forest was a little tricky, but still easy. The one with Diddy Kong in Creepy Castle is no pushover. It's hard unless if you can make the TNT Barrel Kart right next to the other. Otherwise, it's difficult to deal with switching lanes all the time in 60 seconds.
Teetering Turtle Trouble is another easy bonus stage. I usually feed the snakes in order from the upper left. Just make sure you're not moving slow.
Busy Barrel Barrage is another fun stage, but you're limited to your weapon and kill those Kremlings. One hit and you're done for. I hate if they get me at the last second.
Krazy Kong Klamour is easy, and I'm very quick on this. I'm able to glimpse at where the Golden Banana is as the light comes on. Hitting the Kong just wastes time, and undo your Golden Banana hit.
And finally, Stash Snatch is easy, collecting coins as you navigate the maze with enemies. I like to see if I can defeat all the enemies, as well.
So some are fun, easy, or hard, they were a great addition to Donkey Kong 64. Not every Kong can play every bonus stage, however.
