The major feature of 1.37.1 will be resource overriding support. With this thing you will be able to create resource packs which can change many aspects of visuals and scripts.

Things that are possible to override:

• TSC scripts
• Spritesheets of entities, tilesets, backgrounds
• NPC stats table (npc.tbl)
• UI/HUD textures
• Stage names and layout (for pregenerated stages)
• JSON data (which will include all non-TSC strings in 1.37.1 for localization purposes)
• Music and sounds