This is going WAY back, but the "Myth" games (the RTS games Bungie made before they made Halo).
Myth was an RTS game, but you didn't have bases or resources, just a limited number of guys in each mission that you had to utilize effectively. The game was very tough: you were always heavily outnumbered, death was permanent, and your guys weren't much tougher than the enemies, so you wouldn't last long in a stand up fight. You had to use careful tactics to win the day, but (with a small handful of exceptions) the game almost never put you in a position where only one strategy could be used to win the day, even on the tougher missions. There was always alternate ways to find victory (and with a little luck on your side).
Ninja Gaiden 2 did difficulty poorly (to me). I still loved the game, but too frequently the difficulty came about due to either a shitty camera or bullshit attacks (I'm looking at you, incendiary shuriken Ninjas).
Myth was an RTS game, but you didn't have bases or resources, just a limited number of guys in each mission that you had to utilize effectively. The game was very tough: you were always heavily outnumbered, death was permanent, and your guys weren't much tougher than the enemies, so you wouldn't last long in a stand up fight. You had to use careful tactics to win the day, but (with a small handful of exceptions) the game almost never put you in a position where only one strategy could be used to win the day, even on the tougher missions. There was always alternate ways to find victory (and with a little luck on your side).
Ninja Gaiden 2 did difficulty poorly (to me). I still loved the game, but too frequently the difficulty came about due to either a shitty camera or bullshit attacks (I'm looking at you, incendiary shuriken Ninjas).