There are 3 races to play and each are actually different. It's not just changing colours and costumes. The units have different prices and abilities, strengths and weaknesses. So to win strategy needs to change, making the experience rich.

Team games up to 8 players. Friendlist. Chat in game (and out). Tournaments. A huge and very active community.

Ads are" pull", you only watch them if you want to earn in-game money more quickly. It's perfectly possible today forever without seeing any.

No place for luck, only the skill prevails. In particular when all players have the same race, and maps are mirrored.
A rating system ELO style, that matches you with players of your level. Multiple tournaments every months.

There are in app purchases, most are cosmetic and don't affect game play. There's even one which is simply "support our developers".

There are some key purchases which DO affect game play: extra unit types and extra undo turns. However these are available through watching commercials and can also be had permanently without money for the patient by saving the in-game rewards. It does take a long time though.

Undo is the most important one. Get it first.

Variety of maps created mostly by other players (voted if good or bad) make each game different. Combined with necessity to adopt your tactic to which race you and your opponent play and his moves, makes each game unique.

With generally 24h or 12h turns. Notifications when it's your turn