Level progress requiring secrets

[Adno]

I just finished e1m3 Old Time Religion and was stuck trying to find the blue key long enough to give up and consult a guide. It turned out that level progress required throwing a gas can at a wall to open up a small crawlspace to the blue key.

Will this be required in many other levels? I like secrets, but I don't like running into every wall to progress.

[Seekay]

That's just an additional key, a reward for clever lads who want to skip the normal way. Secrets aren't needed to progress the game at all, but they help you out a lot, especially if they contain weapons you wouldn't have found normally!

In case you wonder, this is where you would get the blue key normally. https://imgur.com/piksghJ

You get there after opening the red door of the big house, to the left of the spawn point.

[Reverendo Bizarro]

Ehhhhh no, that's not required to finish the level

[Adno]

Eh? I was trying to find another way to progress for half an hour without success though.

[Reverendo Bizarro]

Then you didn't try very hard, I'd say. Watch after 4:02 to see the path to the non secret blue key https://youtu.be/mB_WHpf_V54?t=242

[Seekay]

You honestly have to try really hard not to go the regular path, lol. The map is designed in such a way that you perfectly loop around, it's no maze.

After you get the red key and swim through the water, you can open the gate, go straight ahead, and open the red door, leading to the blue key. Then, a path opens that leads back underground to where the blue door is, which was where you got the red key in the first place, leading to the level's exit.

Pretty straight forward and fool proof level design, in my opinion.
I guess some people are just extraordinarily bad at navigating levels for some reason. I bet you'd love Turok 2. :p