Altered Beast - Altered Beast is an Action-Adventure, Side-Scrolling, Beat-em-up, Single and Multiplayer video game developed and published by Sega.
Mega Man Revolution - A fan-made 8-bit-style Megaman side scrolling shooter game.
Fist Puncher - Team2Bit developed a great video game named as Fist Puncher is an Action-Adventure, Beat-em-up, Side-Scrolling, Co-op, Single and Multiplayer video game.
Megaman Origins - Between MM3 and MM4 there was a MM adventure, never told, until now:
Devil’s Dare - Devil’s Dare is an Action-Adventure, Beat-em-up, Single and Multiplayer video game developed and published by Secret Base.
Dead Cells - Castlevania-inspired, action platformer with roguelike elements.