Anton Tower puts ANTONBLAST's crew inside Pizza Tower. Everything Anton, Annie and Satan look and sound like is read from your own copy of ANTONBLAST when you press Play.
Character select: pick Anton, Peppino, Noise or Annie (and Satan once he's beaten). Each save file remembers its pick.
ANTONBLAST moves: hold Dash standing still to rev the Clutch (watch the boost bar), let go to Clutch Blast. Land a body slam to Hammer Bounce. Grab becomes a Hammer Swing.
Two-player Swap Mode: your partner follows you as an ANTONBLAST character, and you swap who's in front.
Satan's boss gate in the Tower Lobby: press Up to fight ANTONBLAST's Satan with his own attacks and boss music. Beat him and he's playable.
Peppino's TV is gone, and Pizza Tower's own title screen and Pizza Time stay as they are.
Needs Pizza Tower and ANTONBLAST installed (Steam). Your own Pizza Tower files aren't touched: the mashup plays from its own copy of the game's data.
Pizza Tower is by Tour De Pizza. ANTONBLAST is by Summitsphere. Bundled tools: UndertaleModLib (GPLv3, source included), Magick.NET/ImageMagick, SharpZipLib, .NET. Fan mashup.