The game runs as normal for a little bit but after a while, certain items and menus will have some lag associated with them. Other things run fine... no lag on the game menu, player inventory, walking around, etc.

Things that lag:

• Water placed with a bucket will spread after a brief delay.
• Mining a block with anything (hands, pickaxe, axe, shovel, etc.) will mine the block as normal, but then the block will reappear for a brief moment after the same delay and then disappear again, dropping the corresponding item.
• Right-clicking to cast or reel-in with a fishing rod will cast/reel the line after the same delay. Also, the fish particles now track to where the bobber hit the water initially, rather than where it currently is.
• Eating food takes longer than normal, probably because of the same lag before it recognizes that you've begun eating.
• Right-clicking to open a chest will open the chest inventory after the same delay. Closing said chest closes the inventory immediately, but the chest will visually remain open for a brief moment before closing.
• Attempting to use a workbench, loom, furnace, enchantment table, or brewing stand will open their inventories after a brief delay.
• Attempting to use a bed put you in the bed or give you a message ("...monsters nearby", or "...night and during thunderstorms") after the same delay. Sleeping takes a lot longer.
• Firing a bow will release the arrow after the same delay.
• The day/night cycle. The sun/moon rubberband constantly (see video).

Things that don't lag:

• Opening and closing the player inventory.
• Opening and closing the game menu (pushing [Esc]).
• Opening and closing doors, fence gates, and trapdoors.
• Running, sneaking, swimming, jumping, and climbing.