Flowey literally "closes" your game to start the fight.
Developers have recreated the Omega Flowey battle in pure JavaScript. Search GitHub for “Omega Flowey Web” and look for a live demo link. GitHub.io domains are rarely blocked by corporate or school filters.
: While primarily for the Sans fight, this site is a staple for browser-based Undertale combat. Mechanics and Phases
Flowey returns. But he is no longer a simple talking flower. He has fused with the six human souls and the game’s own save file system. His form is a grotesque, multi-layered abomination: a giant plant head with a television-screen face, surrounded by floating humanoid souls, tentacles, and the UI elements of the game itself. The battle screen tears, the menus become weapons, and your "MERCY" button disappears entirely.
Some trusted unblocked sites host Undertale demos or full HTML5 versions. Look for:
