Game series that only have half of the series released

[GetImOliver]

For NES these games are supposedly sequels:
Goonies 2
Defender 2
Dig Dug 2
Gargoyle's Quest 2
Gremlins 2
Impossible Mission 2
Kings Quest 5

None of them have an official NES first version though I'm sadly wishing that Dig Dug and Goonies were released here in cart form.

A couple of these are based on movies, so I'm guessing the developers didn't want to stick to the original storyline of the movies ala LotR 3rd Age. That's where the "2" comes in, maybe. But is Gremlins 2 based off the movie of the same name? Or was it a kind of unofficial sequel before the movie came out? I know Dig Dug, Defender, and Kings Quest started on different platforms... so they're just continuing on the ol' NES.
Also, was there a Qbert 1 or 2 on the NES? All I know for sure is Qbert 3 on the SNES...

[Tron 2.0]

Another good example would be the Ys series. Only a few came out in English.

TG16 just got Ys 1&2 and III here just IV never got a domestic release.

Even though TTI was supose to give Ys IV a u.s release it didn't happen. At least in the end it, did get a fan translation with added english patch.

Still there is the case of, Ys 1&2 Enternal for the "PC and the PS2" neither got a domestic release wich is a shame.

Heck even that version of Ys got a fan translation as well

[roushimsx]

For NES these games are supposedly sequels:
Goonies 2

Goonies

never played it myself, though. Loved Goonies II!

[Garry Silljo]

Highlander on the Jag CD was supposed to be a trilogy from what I've been told. I want to shoot whoever decided to make a Highlander game and bose it off the damn cartoon instead of the live action series or movies. Dumb.

[Dangerboy]

The US Clock Tower and King's Field Series both started with the 2nd games as the First.

[RevQuixo]

The US Clock Tower and King's Field Series both started with the 2nd games as the First.

Same for Motor Toon Grand Prix...

[roushimsx]

oh!

Everblue 2 and Gungriffon!

Also, the Daisenryaku series has a shitload of games out in Japan and only....2 out in the US?

[devilman]

On a rather more tenuous note, you could include compilations - for example, Sega Ages Vol 1 on the Saturn never got a Volume 2 (in Europe at least). Same goes for Master Games 1 for the Master System... no Master Games 2

[Damon Plus]

Which would be the games included in Master Games 2 if it were created?

Here in Spain, we didn´t get Castlevania 3, because at the time the distributor wanted to get it, Super Castlevania IV was already released, and they tought it wouldn´t make sense (like if having 1,2 and then 4 has some )