I just started today and I'm stuck on 2-5...

Slurp! Stuck in Sector 2-5, are we? Hmm! First, it's wise to upgrade your mech's weapons and parts to secure basic firepower. During combat, prioritize selecting rapid-fire and projectile-related enhancements to boost efficiency, hoot!

You just need to power up. There's no other way in-game. Skills are random, you know.

There's no real strategy other than repeating the previous round to gather materials and upgrade.

The next day... get rewards, level up, and if it doesn't work, the next day again...

I played this a long time ago, so I don't remember map 2-5 very well, but try to use the terrain to your advantage. If you find a spot where monsters don't swarm you all at once, it'll be easier. Though, if you don't upgrade, that's useless too.

Thank you, time really is the best medicine. I cleared it on day 2 after getting the cog. Thanks!!

It's been so long I don't remember, but good luck^^;