For Nintendo Switch Online users, the service is adding four new (old) games this month for the Nintendo Entertainment System and the Super Nintendo Entertainment System:

SNES:

A vertical scrolling shooter, Pop'n Twinbee is the sixth game in the Twinbee series developed by Konami and originally released in 1993 for the Super Famicom. Ships Twinbee and Winbee pick up a distress signal from Madoka, the granddaughter of brilliant scientist Dr. Mardock. Dr. Mardock was once benevolent until a bump on the made him insane. Mardock now wishes for world domination, and only Twinbee and Winbee can stop him.

Smash Tennis is simplistic, but opens the door for lots of skill. A button and B button are strong shot and weak shot, respectively, while the X button provides lobs. Game modes include Exhibition and Tournament. Play through set after set to proceed through and win the tournament and play on eight different courses, three normal and five special.

Both Pop'n Twinbee and Smash Tennis have never been released in the United States.

NES:

In Shadow of the Ninja, the year is 2029 and America is under the rule of Emperor Garuda (we only have 9 years left). Infiltrate his stronghold as you prowl through the shadows. Play as two ninja master from the Iga clan, Hayate and Kaede, as you combat the enemy frontlines in these action-packed stages. Originally released in 1990, Shadow of the Ninja is a side scrolling platformer that allows simultaneous play. Battle through five levels with 16 stages each with an assortment of weapons and skills like katana blades, grenades, and shurikens.

A powerboat racing game, Eliminator Boat Duel puts you behind high-powered water based racing machines as you compete your way through the competition for fame and prize money. Total your winnings to repair and upgrade your boat to remain a step above the rest. Use aggression to your advantage and sink opponents to win $50,000, but be careful. The other racers won't be taking it easy on you either.