Star Runner on the TI 99/4a. I finished the game multiple times when I was 10.

I tried playing it on an emulator recently and I can't even get to level 7 or 8.

It's like a Lode Runner ripoff (but better IMO). The levels are kind of puzzle-like. And you can manipulate the enemies' movement, as the will always try to shadow your own movement. But around the 6th level theres a place where they all fall down in a hole with the last gem (or whatever they're supposed to be). The ladder out of the hole does appear until you have all the gems. So by the time you get the other gems, you can't get to the last gem because the baddies are all stuck in the hole with the gem.

And if you go for the gem in the hole first, theres no way out because the ladder out of the hole doesn't appear until you have all of them.

It seemed so easy when I was kid. But hell if I can figure out the trick as an adult. I know it's some simple trick because most levels in the game have a trick. They're all about problem solving, not about split second timing or luck. But the only way I have gotten past that level as an adult was pure luck and split second timing on my last life.

And obviously there aren't any tutorials or videos to watch to figure out the trick, because it's an unheard of Lode Runner ripoff on the TI 99/4a.