EGA Trek was shareware but by the early-to-mid 90's you could buy the full version at a store for a few bucks. I got my copy off a peg hook at Wal-Mart.
As for new free games- I just started dipping my toes back into PC gaming, so I'm not all up on what's available. Rock Paper Shotgun has a regular series called Free Games of the Week (link is Week 13). This could scratch your free games itch.