diff --git a/osu.Game/Beatmaps/BeatmapDifficulty.cs b/osu.Game/Beatmaps/BeatmapDifficulty.cs
index 6425c7b291..90a60c0f0c 100644
--- a/osu.Game/Beatmaps/BeatmapDifficulty.cs
+++ b/osu.Game/Beatmaps/BeatmapDifficulty.cs
@@ -12,6 +12,11 @@ namespace osu.Game.Beatmaps
     [MapTo("BeatmapDifficulty")]
     public class BeatmapDifficulty : EmbeddedObject, IBeatmapDifficultyInfo
     {
+        /// <summary>
+        /// The default value used for all difficulty settings except <see cref="SliderMultiplier"/> and <see cref="SliderTickRate"/>.
+        /// </summary>
+        public const float DEFAULT_DIFFICULTY = 5;
+
         public float DrainRate { get; set; } = IBeatmapDifficultyInfo.DEFAULT_DIFFICULTY;
         public float CircleSize { get; set; } = IBeatmapDifficultyInfo.DEFAULT_DIFFICULTY;
         public float OverallDifficulty { get; set; } = IBeatmapDifficultyInfo.DEFAULT_DIFFICULTY;
@@ -20,6 +25,15 @@ namespace osu.Game.Beatmaps
         public double SliderMultiplier { get; set; } = 1;
         public double SliderTickRate { get; set; } = 1;
 
+        public BeatmapDifficulty()
+        {
+        }
+
+        public BeatmapDifficulty(IBeatmapDifficultyInfo source)
+        {
+            CopyFrom(source);
+        }
+
         /// <summary>
         /// Returns a shallow-clone of this <see cref="BeatmapDifficulty"/>.
         /// </summary>
@@ -30,7 +44,7 @@ namespace osu.Game.Beatmaps
             return diff;
         }
 
-        public void CopyTo(BeatmapDifficulty difficulty)
+        public virtual void CopyTo(BeatmapDifficulty difficulty)
         {
             difficulty.ApproachRate = ApproachRate;
             difficulty.DrainRate = DrainRate;
@@ -40,5 +54,16 @@ namespace osu.Game.Beatmaps
             difficulty.SliderMultiplier = SliderMultiplier;
             difficulty.SliderTickRate = SliderTickRate;
         }
+
+        public virtual void CopyFrom(IBeatmapDifficultyInfo other)
+        {
+            ApproachRate = other.ApproachRate;
+            DrainRate = other.DrainRate;
+            CircleSize = other.CircleSize;
+            OverallDifficulty = other.OverallDifficulty;
+
+            SliderMultiplier = other.SliderMultiplier;
+            SliderTickRate = other.SliderTickRate;
+        }
     }
 }
diff --git a/osu.Game/Beatmaps/BeatmapInfo.cs b/osu.Game/Beatmaps/BeatmapInfo.cs
index b000862457..796c2b2e90 100644
--- a/osu.Game/Beatmaps/BeatmapInfo.cs
+++ b/osu.Game/Beatmaps/BeatmapInfo.cs
@@ -8,6 +8,7 @@ using Newtonsoft.Json;
 using osu.Framework.Testing;
 using osu.Game.Database;
 using osu.Game.Models;
+using osu.Game.Online.API.Requests.Responses;
 using osu.Game.Rulesets;
 using Realms;
 
@@ -72,7 +73,7 @@ namespace osu.Game.Beatmaps
         }
 
         [UsedImplicitly]
-        private BeatmapInfo()
+        public BeatmapInfo()
         {
         }
 
@@ -100,6 +101,13 @@ namespace osu.Game.Beatmaps
 
         public double TimelineZoom { get; set; }
 
+        public CountdownType Countdown { get; set; } = CountdownType.Normal;
+
+        /// <summary>
+        /// The number of beats to move the countdown backwards (compared to its default location).
+        /// </summary>
+        public int CountdownOffset { get; set; }
+
         #endregion
 
         public bool Equals(BeatmapInfo? other)
@@ -113,20 +121,53 @@ namespace osu.Game.Beatmaps
         public bool Equals(IBeatmapInfo? other) => other is BeatmapInfo b && Equals(b);
 
         public bool AudioEquals(BeatmapInfo? other) => other != null
-                                                        && BeatmapSet != null
-                                                        && other.BeatmapSet != null
-                                                        && BeatmapSet.Hash == other.BeatmapSet.Hash
-                                                        && Metadata.AudioFile == other.Metadata.AudioFile;
+                                                       && BeatmapSet != null
+                                                       && other.BeatmapSet != null
+                                                       && BeatmapSet.Hash == other.BeatmapSet.Hash
+                                                       && Metadata.AudioFile == other.Metadata.AudioFile;
 
         public bool BackgroundEquals(BeatmapInfo? other) => other != null
-                                                             && BeatmapSet != null
-                                                             && other.BeatmapSet != null
-                                                             && BeatmapSet.Hash == other.BeatmapSet.Hash
-                                                             && Metadata.BackgroundFile == other.Metadata.BackgroundFile;
+                                                            && BeatmapSet != null
+                                                            && other.BeatmapSet != null
+                                                            && BeatmapSet.Hash == other.BeatmapSet.Hash
+                                                            && Metadata.BackgroundFile == other.Metadata.BackgroundFile;
 
         IBeatmapMetadataInfo IBeatmapInfo.Metadata => Metadata;
         IBeatmapSetInfo? IBeatmapInfo.BeatmapSet => BeatmapSet;
         IRulesetInfo IBeatmapInfo.Ruleset => Ruleset;
         IBeatmapDifficultyInfo IBeatmapInfo.Difficulty => Difficulty;
+
+        #region Compatibility properties
+
+        [Ignored]
+        public int RulesetID => Ruleset.OnlineID;
+
+        [Ignored]
+        public Guid BeatmapSetInfoID => BeatmapSet?.ID ?? Guid.Empty;
+
+        [Ignored]
+        public BeatmapDifficulty BaseDifficulty
+        {
+            get => Difficulty;
+            set => Difficulty = value;
+        }
+
+        [Ignored]
+        public string? Path => File?.Filename;
+
+        [Ignored]
+        public APIBeatmap? OnlineInfo { get; set; }
+
+        [Ignored]
+        public int? MaxCombo { get; set; }
+
+        [Ignored]
+        public int[] Bookmarks { get; set; } = Array.Empty<int>();
+
+        public int BeatmapVersion;
+
+        public BeatmapInfo Clone() => this.Detach();
+
+        #endregion
     }
 }
diff --git a/osu.Game/Beatmaps/BeatmapMetadata.cs b/osu.Game/Beatmaps/BeatmapMetadata.cs
index 387641db40..dc5517375d 100644
--- a/osu.Game/Beatmaps/BeatmapMetadata.cs
+++ b/osu.Game/Beatmaps/BeatmapMetadata.cs
@@ -44,5 +44,15 @@ namespace osu.Game.Beatmaps
         public string BackgroundFile { get; set; } = string.Empty;
 
         IUser IBeatmapMetadataInfo.Author => Author;
+
+        #region Compatibility properties
+
+        public string AuthorString
+        {
+            get => Author.Username;
+            set => Author.Username = value;
+        }
+
+        #endregion
     }
 }
diff --git a/osu.Game/Models/RealmNamedFileUsage.cs b/osu.Game/Models/RealmNamedFileUsage.cs
index 17e32510a8..801c826292 100644
--- a/osu.Game/Models/RealmNamedFileUsage.cs
+++ b/osu.Game/Models/RealmNamedFileUsage.cs
@@ -31,5 +31,15 @@ namespace osu.Game.Models
         }
 
         IFileInfo INamedFileUsage.File => File;
+
+        #region Compatibility properties
+
+        public RealmFile FileInfo
+        {
+            get => File;
+            set => File = value;
+        }
+
+        #endregion
     }
 }
diff --git a/osu.Game/Rulesets/RulesetInfo.cs b/osu.Game/Rulesets/RulesetInfo.cs
index 91a3d181f8..99b4f5915f 100644
--- a/osu.Game/Rulesets/RulesetInfo.cs
+++ b/osu.Game/Rulesets/RulesetInfo.cs
@@ -33,7 +33,7 @@ namespace osu.Game.Rulesets
         }
 
         [UsedImplicitly]
-        private RulesetInfo()
+        public RulesetInfo()
         {
         }
 
@@ -83,5 +83,11 @@ namespace osu.Game.Rulesets
 
             return ruleset;
         }
+
+        #region Compatibility properties
+
+        public int ID => OnlineID;
+
+        #endregion
     }
 }