Four Dimensional Girl Lydia

About
Four Dimensional Girl Lydia is a game released by Champion Soft in 1983. Despite functioning like the at the time popular ADV type genre, it's intention was to be closer to a sci-fi movie. The genre is what they themselves described it as.

The game is graphically quite a bit stronger than their other titles at the time. This can also be explained by the fact that the dev team is actually quite large for a Champion Soft game.

The game includes some stereoscopic 3D scenes which isn't too surprising as it was popular with movies back then.

Diskettes weren't quite as common as you'd think back then and this meant that this got a tape release. A large one at that, as the game required 4 tapes. Not sure if that and the extra waiting time would be worth the 2000円 saved.

Story
The setting is a far future where the mystery of the Bermuda Triangle hasn't been solved. The President of the US has disappeared and it's your task to investigate.

Gameplay
The game mostly progresses by itself until certain key points. The adventure bits use a text parser and let you type text.

There's also a "3D" forest maze at a later stage. You move by using F, R, L or D as directons.

The climax for the gameplay has you play a basic vertical space shooter where you need to kill 30 ships in 5 tries. The music played at the start of the mini-game is dubiously legal, but I guess it did see a release that year.

Walkthrough
The walkthrough is from this blog

First scene with Pigumon (the pink blob), might not be needed as I typed the wrong stuff and beat the game:

(キミハダレダネ？)　任意のコマンド

(ココノホシヲシッテルカイ)　シッテル

(ドウシテキタノ)　バミューダ

Password: バミューダ

Computer room:

チチ

SOS

シーザー

シハイ

メモ

バミューダ

デネブ

トピアセイ

ジゲン

リディア

トライアングル

ブラックホール

ホワイトホール

任意の単語*7 (any word x7)

3D Maze: F, L, R, R, L, R, L

Lydia (first meeting):

サワル

タスケル

Password: 5ジゲン

Space king Ceasar (green haired guy):

リディア

モクテキ

チキュウ

リディア

ヘイワ

リディア

Lydia 2:

タスケル

デキル

アレ

バミューダ

ホワイトホール

ブラックホール

5ジゲン

Password: トピアセイ

Kill 30 enemies in the shooter scene in 5 lives. Don't worry, you can retry (even if you win).