Mindustry 5.0 is now out, with many new exciting features. These include: Schematics. Select an area, then paste it somewhere else or save it for later use. Rotation and flipping is fully supported.
Automatic drone rebuilding. Phantom drones will now automatically replace broken blocks.
New placement controls. Edit your build queue on the fly, remove specific blocks or rotate existing ones. For planning on multiplayer servers, building can now be paused and resumed with a keybind.
Mods. Create and share your own modifications of the game through a simple json-based system. No knowledge of programming is required. Take a look at the example mod repository to see what this looks like. Documentation is currently a work in progress. Note that modding is currently unstable. Report any bugs you find using the link in the game. Full patch notes:

• Added inverted sorters: flip item output directions
• Added JSON config-based modding [Alpha, may be very unstable]
• Added block schematics: save and share your designs [Desktop]
• Added placed block rotation: Hold [R] and use the scrollwheel to rotate a block [Desktop]
• Added saving of blocks broken after enemy attacks
• Added phantom drone rebuilding of broken blocks
• Added radial tech tree layout
• Added autotiling for blocks in build queue and selection
• Added zooming and panning in tech tree/campaign select
• Added username labels to minimap [Contributed by Maxattax97]
• Added targeting priority for turrets/units: when targeting blocks, turrets will be attacked first
• Added new loadout select dialog
• Added link to Mindustry subreddit
• Added banning of blocks in ruleset
• Added internal plugin methods for switching servers and updating game rules
• Made incend bullets set enemies on fire instead of just setting everything on fire
• Made build requests be replaceable in build queue [Contributed by @clfer]
• New building system for desktop; supports editing the queue and pausing building
• Added power laser opacity slider [Contributed by azureblue]
• Fixed input not working with different keyboard locales
• Improved zone objectives: finishing attack maps unlocks next zones/configuration, waves no longer needed
• Increased minimum FPS to 15 to prevent game freeze
• Changed 'plugins' to 'mods': function the same way, but with more capabilities
• Tutorial text tweaks
• Disabled player-player and player-drone collisions
• Fixed crashing when launching in offline mode [Steam]
• Lots of other various bugfixes

Gameplay

• Create elaborate drills and conveyor designs to move resources into your Core
  
• Use production blocks to create a wide variety of advanced materials
  
• Build drones for automatically mining resources, assisting in building and protecting your base
  
• Distribute liquids and fight constant challenges, like outbreaks of fire or enemy flier raids
  
• Get the most out of your production by supplying optional coolant and lubricant

Campaign

• Advance through 12 replayable built-in zones with randomized spawn points
  
• Collect and launch resources
  
• Research new blocks to fuel progress
  
• Configure launch loadouts to bring resources to each zone
  
• Variety of mission objectives and goals
  
• Invite your friends to complete missions together
  
• 120+ technology blocks to master
  
• 19 different types of drones, mechs and ships
  
• 50+ achievements to complete

Gamemodes

• Survival: Build turrets to defend from enemies in tower-defense based gameplay. Survive as long as possible, optionally launching your core to use your collected resources for research. Prepare your base for intermittent attacks from airborne bosses.
  
• Attack: Build factories for units to destroy the enemy cores, while simultaneously defending your base from waves of enemy units. Create a variety of different types of support and offensive unit to assist you in your goals.
  
• PvP: Compete with other players on up to 4 different teams to destroy each other's cores. Create units, or attack other bases directly with your mechs.
  
• Sandbox: Play around with infinite resources and no enemy threat. Use sandbox-specific item and liquid source blocks to test out designs, and spawn in enemies on request.

Custom Games & Cross-Platform Multiplayer

• 12 built in maps for custom games, in addition to campaign
  
• Play Co-op, PvP or sandbox
  
• Join a public dedicated server, or invite friends to your own private session
  
• Customizable game rules: Change block costs, enemy stats, starting items, wave timing and more
  
• Mix&match gamemodes: Combine PvP and PvE gamemodes together

Custom Map Editor

• Paint terrain with an editor UI
  
• Edit and preview structures in-game
  
• Configurable tool modes: Change how each tool functions
  
• Powerful map generation system, with many different types of filters for procedural manipulation of terrain
  
• Apply noise, distortion, smoothing, erosion, symmetry, ore generation and random terrain to your maps
  
• Randomize and configure ore generation, as well as placement of river and resource tiles
  
• Configure enemy wave layouts
  
• Share exported maps on the Steam Workshop
  
• Customize base map rules
  
• Use 75+ different environmental blocks

• Memory: 1 GB RAM
• Graphics: Anything with OpenGL 2.0 Support
• Storage: 100 MB available space