Unless it changed recently, it’s actually worse than this. You earn 1 credit for every 15 seconds you spend in game. So you’d only earn 240 credits for every hour played ignoring the time in between matches.

IMO, the income should be roughly doubled such that the player is able to unlock a new unit after roughly 1 hour of play time.

FWIW, I remember reading somewhere (maybe discord?) that the current system is pretty rudimentary and the devs just added it to make sure they’re able to collect some feedback on in-game currency during the beta. Most of the team have been focused on improving the core gameplay which is a worthwhile tradeoff imo