Wall World
24 Achievements
GOG
Endure and Survive
Survive for a while
30.8%
How to unlock the Endure and Survive achievement in Wall World - Definitive Guide
After the 20-minute mark the main baddy will show-up and block you into an area. You must destroy the two purple flesh-bags on his body to force him to retreat and thus unlocking another 20 minutes to explore & upgrade.
Of note, most weapons will struggle to reach the boss, let alone be accurate enough to consistently hit the pulsing purple warts. I'd recommend upgrading the missile system on your spiderbot ASAP as the missile will ignore all enemies while the boss is out and try to pop the bulbous blisters. After a few upgrades it will just take two missiles to complete phase 1.
Of note, most weapons will struggle to reach the boss, let alone be accurate enough to consistently hit the pulsing purple warts. I'd recommend upgrading the missile system on your spiderbot ASAP as the missile will ignore all enemies while the boss is out and try to pop the bulbous blisters. After a few upgrades it will just take two missiles to complete phase 1.