Without energy supply, the death of billions is imminant! We need the three control diamonds to engage backup systems. Use the shielded suit and the powerglove to protect you against the maintenance robots. Help us, you’re the only hope! – [Author’s Description]
[Download Vice (emulator) for various platforms]
(via RGCD C64 Cartridge Development Competition 2013)
This opens up eventually (later levels remind me of Metroid 1 where it’s easy to get lost among repeated room shapes), but man is the first level repetitive and linear even when you don’t count the mandatory backtrack to the first screen.