Student or Learner
I'm in trouble with the underlined sentence. What does It convey?
Also keep an eye on the Humble Bundle. These ‘pay what you want’ packages are held for two weeks every month or so. The folks at Humble have been fantastic supporters of Linux as a gaming platform, single-handily ensuring the Linux debut of many touted titles.
I am not a teacher.
The thread title says 'single-handedly' but you've underlined 'single-handily', which is nonsense.
It means that Humble Bundle Inc. are supporters of Linux as a gaming platform, and as such have ensured (on their own/with no help from anyone else) that many of the games would be made available for play on Linux based systems.