Forums GTA New to the forums, first question!

Hey everyone! So I'm a bit of a completionist, and I'm doing a 100% marathon of all the GTA games in the series. I'm just wondering, is it possible to 100% the "original 4" GTA games (1, 2, 1969 & 1961)? My initial impression/guess is no because so many things become missable if you fail them and you only need a certain score to get to the end of each game... But opinions are more than welcome! Thanks to anyone who answers!