I didn't play Gods Unchained but Splinterlands is different from other TCGs as it is also an auto-battler. Meaning the matches are quick and light to play. You take some time (up to 2.5min) to assemble a team out of your cards before the fight by using the right strategy for the ruleset which is different every game. Your opponent does the same and then your monster cards will battle it out in an automated mode to see which team was picked best.
Also Splinterlands does not have transaction fees so it becomes easier to buy and sell cards (no Gas needed as for ETH tokens).

Trying is free, so you may as well sign up. If you like the gameplay and want to unlock reward earnings the starter pack is a 10 USD one time investment.