No, because the game does not exist. However, you can emulate Metal Slug 1-6 (via Neo Geo, MAME, or PS1/PSP emulators) on Android using apps like RetroArch or PPSSPP .
Almost certainly fake. Most videos use footage from Metal Slug: Awakening (mobile) or Metal Slug Tactics (PC) with a fake "8" edited onto the title screen. Others are stolen from fan games. metal slug 8 apk
Stay safe, soldier – and keep shooting until you see the "Mission Complete" screen. No, because the game does not exist