Hi Rybags. I suggested slowing Encounter down because it becomes extremely fast in the later levels, especially in the tunnels between levels. Not sure if there are any hacked levels with extra or infinite lives.
Regarding the C64 Endings site, it’s a defunct website that is worth visiting to view the endings of many games. Even though it’s intended for C64 games, there are plenty of titles that were really similar on both Commodore and Atari 8-bit platforms. Oh, and you can see that Encounter has no ending in the section labeled “507?Games with no endings”.