I have thought about this for a bit longer. How can I keep the game function time-based (as it is a simulation game) while not stressing the player and forcing decisions? I found a hybrid solution for this. When you place a tile, the timer is paused. In this way, the strategic playing remains, as the player can take time on the decisions, while also the challenge of combining tiles cleverly persists. I have already gametested this a bit and I think it improves the game experience. There are also a few other advantages: This doesn't complicate the game further, as it is complicted enough. I don't have to change much of the code.