xonix
a really funky game that was on our second ever computer which ran on dos... you had to navigate a little blob into the dangerous area to take more safe space but doing a whole rectanle (or other shape) whilst avoiding the bouncy blobs which kill you, or touching your line before it's sealed into a safe space cos that kills you too. as you go up levels there are more bouncy blobs which move faster...
i loved playing xonix