Monsterinn (the original title doesn't have a space for most games on this system, for some reason) for Pyuta reminds me of the concept of Heiankyo Alien for VIC-1001. Yeah, they look nothing alike, the perspective is quite different and video game graphics had some time to refine between those releases. And the Pyuta is (somehow!) a 16-bit system, so we can cut the VIC-1001 a bit of slack. But the ideas really are similar. Smash a hole in the ground, wait for an enemy to fall into it, and then finish them off before they manage to escape. Monsterinn adds one novel concept - a transportation door. Enter the door and it takes you somewhere else. Ideally someplace safer than you're currently at, but no guarantees!

Wait a minute! It just occurred to me, maybe the title was being quite clever. Monsterinn, like, monster in the hole? Actually the original katakana could just as easily be transcribed as "monster in", so it seems a plausible theory.