Direct quote
“When you get four enemies or even four bullets on the screen at once, the screen starts blinking and it just doesn't work. I tackled that problem by taking a different approach--hiding from enemies and not fighting them.”
What it documents
Kojima said that after the "no" to his first game he was assigned to make another war game, and that making it for the MSX was difficult because of the sprite limit: when four enemies or even four bullets were on screen the display started blinking and it did not work. He tackled the problem by taking a different approach—hiding from enemies instead of fighting them—so he could limit how many enemies and bullets were shown at once.
Source
Gamers Today, interview with Hideo Kojima (undated page, retrieved from web.archive.org). View source ↗
“After my first game, Lost Warld, was given a "no" by the company, I was told to create another war game.”