In case anyone doesn't know Alien Soldier is awesome. The entire game is pretty much a boss rush, but it has a large variety of bosses that are all unique. It's also ahead of its time with the lower difficulty even letting you adjust the speed of the game, so you can slow things down if a boss is giving you issues, to make it easier to dodge attacks.
So despite the fact it's from Treasure who was well known for hardcore action games, it's very accessible to a larger audience if they choose the lower difficulty.