Ok so basically, to put it shortly, it’s like the theming of Half-Life with the gameplay of Pizza Tower, with an added dose of stealth.
Basically, Phantom is a normal stealth operative/soldier in a semi-futuristic society. Basically a bunch of Xarranians invade the planet and Phantom has the plan to sneak into their base and destroy them from the inside. To do this he must travel through 5 different environments (basically worlds like in Mario) with different gimmicks and difficulties. Phantom is armed with a futuristic sword rather than a katana (because realistically, a katana wouldn’t do anything), as well as a robot exoskeleton that lets him run immensely fast and survive long falls, giving it that speed-action feel that made Pizza Tower so engaging. The combat is basically just M1 to attack, M2 to block. M1 in the air lets you do a spinny attack, and M1 while running lets you stop without sliding forwards.