• CEO calculates a danger grid and sightlines so you don't have to. Pieces promote instantly to maintain the blazing pace of this game.
  
• Building custom armies and climbing the ranked ladder is super fun!
  
• Each piece has an associated cost/value which limits/balances the armies you can build. Having multiple extra strong pieces will result in the rest of your army being weaker.
  
• Each piece and tier has a unique moveset which can be easily viewed by mousing over said piece. Many abilities like move, attack, etc. are reused frequently so there's not too much to learn.
  
• This game is unusually free2play friendly. You can earn premium currency from the daily challenge and buy/sell pieces/currencies on the market to get what you want. You won't have immediate access to all pieces and strategies but it's not needed to get to Grandmaster rank.
  
• The game has been updated by 1 man for years with quality of life improvements and cool features.
  
• The only downside is the outdated user interface, which will be jarring for new players. A few UI options are only available in battle.

This is likely the best chess variant, the best CCG, and one of the best games I've ever played. It takes advantage of the video game medium to do things that would be difficult in a board game.

Seriously, play this.