Games: Fantasy Zone (Arcade/1985), Fantasy Zone 2 (Master System/1987)
Mascot for: Sega
This adorable guy is actually a living spaceship who fights all kinds of ridiculous invader enemies in the Fantasy Zone (which must be the opposite of the Phantom Zone). Due to its non-traditional pastel colors and light tone, the game is often referred to as a "cute 'em up." Speaking of cute, Opa-Opa also has a brother named Upa-Upa and a dad named O-Papa. For some reason, they forgot to mention the matriarch of the squad, O-Momma (LOL).
What happened: Fantasy Zone was released during that painful period in which Sega was desperately trying to find a mascot (Alex Kidd would meet the same fate). Even though Opa-Opa was cute, kids just couldn't relate to him (c'mon, he's a spaceship). Jokes aside, he wasn't a strong enough character to carry a big franchise.
Hard to get personality out of a character on screen that early and I guess that's what they needed. But what a great naming convention!
Yeah, the name's are funny (they just left out the mom)
I enjoy playing these, but I die pretty quickly, in much the same way everything in the path of Opa-Opa is obliterated with laser beams and meets a horrible, slow fate.
Yes, but everything is so cute
I love cute-em-ups. TwinBee, Fantasy Zone and some others I haven't played yet. I love the art design of them and they tend to be a touch less difficult than most Shmups, but just a touch.
I was able to beat Pop n' Twinbee last year, and it was pretty great (although still tough)
Oh man, one of my reasons to get a Switch. I just can't justify it right now though.
Opa-Opa? Never heard of this. Yeah, it's kind of hard to relate to a sensient spaceship. 
But at least they tried
I have a little Opa Opa figurine on my desk. I like the fact that Opa Opa was a bonus icon you could collect in classic SEGA games like Zillion. Did you know that Fantasy Zone and Space Harrier are set in the same universe? That's why you see Opa Opa in Planet Harriers. Did you ever play Sonic and SEGA All-Stars Racing? Opa Opa was playable in that one. Also in Project X-Zone, my pretend girlfriend Ulala from Space Channel 5 uses Opa Opa as an attack.
Neat. I guess Sega was trying to build a shared universe with all their characters but it didn't pan out.