Actually, there are two secret areas in level 1. There's also some secret food at the start of level 3 iirc; just smash every empty space.

The level information is stored in such an awkward way that it is practically unmoddable. Each level has its own (mostly copy-pasted) code routine with a lot of hardcoded behaviour. For example, level 1 is the only level with secret areas; the first one is at the jumping fish (screen 6, counted from the start, not using the in-game data screen number), and the second one at the third screen after landing; just left of a ladder leading down to water (screen 14, again, counted from the start). The wrap areas for those screens are hardcoded in the code routine for the first level. Other levels simply don't have this code, meaning any attempts to add secret screens to them is futile.

https://moddingwiki.shikadi.net/wiki/Prehisto … ik_Level_Format

Here's a map of the first level, including both secret areas:
https://www.vgmaps.com/Atlas/AtariST/index.htm#Prehistorik

In my opinion there are more secrets in Prehistorik 2 in the first few levels than in the latter levels. They've probably listened to John Romero's golden rule of level design:

Finish the first level last. Because then you’ve learned everything about the game’s level design, and you’re going to put it all in the first level where you want people to get excited anyway.

https://www.mcvuk.com/development-news/video- … e-playing-doom/

Thanks for the great reply, never knew about the second water secret in level 1 will have to go check it out. Very nice file how it is all mapped out.

I know in certain spots there is hidden food, there is a banana at the start of level 1 but was more curious about hidden screens rather.

I actually find it with alot of games the first level or first few are most enjoyable, I guess that rule stands.