I've tried to get to both entrances too but no luck
#1st Spearmaster Playthrough Help?
fading locust
tardy forum
Firstly, it's recommended not to use online resources like maps, as it can ruin the intended experience of... wandering around lost (it's more fun than it sounds I promise-)
If you continue to use maps, it's your choice, though 
As for your question, I believe you just need to find another way around to reach that gate 
unique hollyBOT
Reposted starting message
Hey guys, I'm on my first playthrough of Spearmaster and I've kinda entered a roadblock. I went to Moon first and once given the mark of communication, she told me there's a bridge between her and FP, I'm assuming it's this gate? But I have no idea how to enter it. I'm currently in the circled area but have no idea how to get to this gate. Any help?
tardy forum
LTTM and FP kind of have a few rooms like that, where you can only go through it one direction based on where you entered from, as a little crossroads/teaser of other rooms
(In this case, I guess you can literally tell it's one of those types of rooms, because the room ID is "CROSSOVER" )
fading locust
Ok gotcha, I'm just confused because I tried going here and I couldn't find a way in lol 😠I'll keep wandering around
tardy forum
(And, again (this is the last time I'll say it I promise-) , it's recommended not to use online maps on a first playthrough)
If you need any further help, or just want to document your playthrough, feel free to come back here
tough yacht
And also feel free to ping Felpers
fading locust
I ended up finding my way actually sorry lol I think I just got a little lost