Fixed #2917

core/src/mindustry/content/UnitTypes.java

@@ -1544,7 +1544,7 @@ public class UnitTypes implements ContentList{
                 xRand = 8f;
                 shotDelay = 1f;
 
-                bullet = new MissileBulletType(4.2f, 25){{
+                bullet = new MissileBulletType(4.2f, 30){{
                     homingPower = 0.12f;
                     width = 8f;
                     height = 8f;
@@ -1552,8 +1552,8 @@ public class UnitTypes implements ContentList{
                     drag = -0.003f;
                     homingRange = 80f;
                     keepVelocity = false;
-                    splashDamageRadius = 25f;
-                    splashDamage = 25f;
+                    splashDamageRadius = 30f;
+                    splashDamage = 35f;
                     lifetime = 56f;
                     trailColor = Pal.bulletYellowBack;
                     backColor = Pal.bulletYellowBack;

core/src/mindustry/ctype/UnlockableContent.java

@@ -22,7 +22,7 @@ public abstract class UnlockableContent extends MappableContent{
     /** Whether this content is always unlocked in the tech tree. */
     public boolean alwaysUnlocked = false;
     /** Icons by Cicon ID.*/
-    protected TextureRegion[] cicons = new TextureRegion[mindustry.ui.Cicon.all.length];
+    protected TextureRegion[] cicons = new TextureRegion[Cicon.all.length];
     /** Unlock state. Loaded from settings. Do not modify outside of the constructor. */
     protected boolean unlocked;
 

core/src/mindustry/game/DefaultWaves.java

@@ -339,6 +339,14 @@ public class DefaultWaves{
             shieldScaling = shieldsPerWave;
         }});
 
+        //shift back waves on higher difficulty for a harder start
+        int shift = Math.max((int)(difficulty * 15 - 5), 0);
+
+        for(SpawnGroup group : out){
+            group.begin -= shift;
+            group.end -= shift;
+        }
+
         return out;
     }
 }

core/src/mindustry/ui/dialogs/ResearchDialog.java

@@ -400,7 +400,8 @@ public class ResearchDialog extends BaseDialog{
                 }
             }
 
-            return false;
+            //can always spend when locked
+            return node.content.locked();
         }
 
         void spend(TechNode node){
@@ -414,7 +415,7 @@ public class ResearchDialog extends BaseDialog{
                 ItemStack completed = node.finishedRequirements[i];
 
                 //amount actually taken from inventory
-                int used = Math.min(req.amount - completed.amount, items.get(req.item));
+                int used = Math.max(Math.min(req.amount - completed.amount, items.get(req.item)), 0);
                 items.remove(req.item, used);
                 completed.amount += used;