Unless you are Japanese, there is a good chance you never had a Turbografx-16 or any gaming something-or-other that was ever manufactured by NEC. There is a good chance you have played something that HudsonSoft was involved with, as they were a driving force behind the system ever being released in North America. They have had their hands in a lot of pies over the years but the TG16 was their major foray into becoming a major player in the home gaming industry. Unfortunately for them, the TG-16 didn't take off in the US or Canada, probably because there was too much competition from Nintendo and Sega at the time.
Because I had a next door neighbor friend that is around my age that ended up with almost anything because his parents were wealthy and got him just about anything he wanted, I was privy to a TG-16 and likely wouldn't have been had it not been for living across the street from him. I think the world missed out on a great system by ignoring the Turbografx because some of my best gaming memories come at the hands of that machine. Some of them were downright bizarre. Bonk was the TG's attempt at competing with Mario and Sonic and when you think about it, it was really a good choice for them to make.
As Bonk you play the role of a baby caveman with an attitude and you don't just jump on enemies' heads like you would with Sonic or Mario, you smash them with your gigantic head.
I think that the people behind the TG-16 were aware that they couldn't compete with Mario's widespread appeal and childlike operation nor could the compete head-on with the slick and cool persona of Sonic, so instead they went for a whacky and kind of gross "face" for the company.
Bonk would do the usual platforming between impractical things like clouds and strange platforms that if they existed in real life would definitely collapse but the way in which he dispatched his foes was a bit more funny that other games. He could also attack enemies without jumping simply by head-butting them, which was always kind of funny.
Want to climb a wall? Well you can.... by using your teeth. It's silly things like this that are featured throughout the entire game and it was definitely intentional. Bonk could also collect enough items in order to go into a rage mode that would allow him to freeze all enemies on the screen as well as become temporarily invincible. It was pretty cool but to be totally honest here, it was more repetitious than both Mario and Sonic games.
The bosses were inventive and were more humorous than either Mario or Sonic and I think this was intentional because the TG-16 was dealing with relatively limited hardware and couldn't really compete with the Genesis or SNES on graphical capabilities.
Bonk's Adventure was a game that will forever stay in my mind simply because of how totally unique it was. It wasn't a fantastic platformer by any stretch but it was a game that would keep you hooked just because of how completely absurd it was. Mario and Sonic were more slick and fast-moving (especially Sonic) but Bonk had a weirdness factor that the other two franchises simply couldn't compete with.
The Turbografx-16 completely flopped in the western world but was a top seller in Japan. This is made even more evident by when they released a "min" version of the console, nearly half of the games on the thing were never even translated into English. This was a time when space shooters were immensely popular in Japan so most of these games never made it across the Pacific. Bonk was available globally though and for a while there he was their mascot in an attempt to gain more of a player-base. It didn't work very well for NEC though, as the system only sold 750,000 units across all of North America. Compare this to the nearly 6 million that they sold in Japan and it is easy to understand why they abandoned marketing in the United States and never even attempted to release in Europe. The real winner in all of this was Hudson Soft because they had a deal in their contract with NEC that they would be paid for ever console they manufactured whether they were able to sell them to the public or not.
Regardless of how poorly the TG-16 did in USA, I still found it, and Bonk to be important parts of my gaming memory. I got my hands on a mini shortly after launch and don't regret spending that $100 at all. Oh, and it has 3 Bonk games on it!