NHL Hitz 20-02 is a single-player and multiplayer arcade-style ice hockey game. The game adapts the basic rules and setting of professional hockey into a fast-paced, exaggerated format. Matches are played three-on-three with goaltenders, creating wide-open ice and emphasizing speed, heavy body checks, and high scoring. Penalties are removed, and play rarely stops, keeping the focus on constant action. The presentation exaggerates the sport with over-the-top hits, fights, and momentum shifts, offering a different experience than simulation-based hockey titles.

Core gameplay revolves around quick passes, slap shots, and aggressive checking. The control scheme is simplified to allow easy access to shooting, passing, and deking, while defensive play emphasizes physicality and intercepting the puck. Players can fight during games, with fights determining which player returns to the ice after a brief skirmish. Matches can be won by outscoring opponents in the set period, though the shortened team size and rule-free environment often result in high-scoring games.

Several modes are available. Exhibition mode allows quick matches between any two teams. Season and championship play offer structured progressions through schedules and playoffs. The Franchise mode enables the creation of a custom team, including designing logos, uniforms, and player names. Over the course of the franchise, attribute points and credits are earned through wins and performance, which can be spent to improve player abilities and unlock extra content. The game includes a number of hidden extras and unlockable items. Completing objectives or meeting certain conditions can reveal secret teams, fantasy arenas, and novelty characters outside the standard NHL roster.

Multiplayer is supported both locally and through system-linked play, with the emphasis on competitive head-to-head matches.