Here's a classic bit of puzzling. Heavy Hogur, from Swedish indies, Spelagon, is the sort of puzzler that would have fit in well during the Amiga days. And indeed today. You play a fiery dwarf who's somewhat over-familiar with gravity, who must mine all the crystals from a level before reaching the exit door. However, the majority of the tiles he walks across will crumble down a level after Hogur's stepped upon them. Since he can't climb, it's about figuring the correct route that won't leave him stranded.
This is a pretty generous demo, too. There are a hefty 27 levels available, of what must be around 100 in the full game, but you have to get to them quickly. There's about an hour of free play time. And the overly-easy ones don't last long - you're quickly being challenged.
The game itself looks relatively pretty. It's in isometric 3D, with some cute animations. However, it's also a tad glitchy - nothing game-breaking, but it flashes and pops occasionally. But importantly, it offers an old-fashioned collection of puzzles, which are pretty satisfying to solve. It's Spelagon's second game, their first being Mulver. You can get the full game for a mere $10.
Here's the trailer, and you can get the demo here.