fixed ui on ultrawide display
fixed towers not scaling properly on packs display
fixed shattered ice crash
moved stop sign down a tier
nuclear plant radioactive dmg at level 4: 16 -> 20
fixed buggy behaviour in certain particle effects
made 'escape' exit the pause menu

optimisations (these shouldn't impact gameplay)
made plots pre-draw themselves to cut down on draw calls
made aoe effects all refer to the same enemy loop
made tower targeting and update get calculated within the enemy update loop