Okay, I'm going to go into full shill mode for today's classic.
Zombie Shooter 2
...no, not that. That's just included for the sake of completeness. The classic... is actually an indie game, but from far enough back that it also fits the 'classic' banner (I was playing it in university in 2000!)
Drod 1+2+3
(That's King Dugan's Dungeon, Journey To Rooted Hold, The City Beneath)
Don't underestimate these. They look, well, I think 'functional' is fair, but they are *supremely* well-designed puzzle games - genuinely, some of the best puzzles I've played. Some people might be familiar with a
very old game, often used as a tutorial to programming, known variously as "Daleks", "Zombies", "Robots"; several mindless enemies home in on you, each turn you move, they move, and so on - and your objective in that game is to get them to collide either with one another or with the wreckage created when they hit each other.
DROD expands on that premise... massively. The core enemy is the roach, which has the mindlessly-following-you aspect going on. First big change is that your character is given a sword; the sword can be rotated around you (with each 45 degree movement taking a turn), and if your sword ends your turn in a roach's space, it gets splatted. And you simply have to clear every room of the dungeon of vermin.
Except... the room layouts get difficult. We start to get tiles that can only be trod on once, tiles that can only be exited a certain way, switches to open doors. And new enemies appear. How about a roach queen, who lays eggs all around her every thirty turns which hatch into roaches and runs directly *away* from you. How about eyeballs, which stand still most of the time but charge you if you step into their line of sight. How about tar, which can only be cut along a straight edge, while the corners are indestructable? How about tar
mothers, who make the tar grow every few turns? How about goblins, who are smart enough to home in on the player but run from the sword? How about spiders, who are invisible if they're not moving? How about serpents, who can only be killed by trapping them in a dead end?
... and that's just the monsters in the *first* game. Loads of monsters, relentless creativity in designs of dungeons. It's just... really really good, if you want a cerebral, strategic puzzle game.
Oh, yeah. And there's a level editor, and a bunch of downloadable levels.
I've been lamenting the fact that it hasn't been greenlit for a while. GoG are doing the right thing here.