Tier IV

New

• Every specialised tower can now be upgraded to tier IV: all 48 branches, from Inferno to Ziggurat. Ultimates still stop at tier III
• Each tier IV is a signature upgrade: a big jump in damage plus one boost that fits the tower, such as a wider blast, one more chain jump, a longer or stronger slow, faster poison, a stun chance, a bigger aura, longer range, or shooting flyers first
• A tier IV costs twice as much as tier III, so it competes with buying another ultimate as the late-game gold sink
• Tier IV shows as IV everywhere: on the upgrade button and its tooltip, in the info panel's upgrade tree, the catalog and the score screen. Upgrade tooltips now also highlight what the signature changes

Balance

• Archer, Ice Shot, Focused Beam and Wrath shoot flyers first at tier IV, giving Gale, Frost, Storm and Light a dedicated anti-air option late

Improvements

• Branch towers now show their real tier in the HUD (an Inferno you just specialised is tier II, not tier I)