Nice job, you got the best score I’ve seen yet. You’re right that the game isn’t really balanced around untimed mode. Since there’s no way to clear tiles, space will eventually fill up and force a game-over. In my initial plan, I wanted to let the player draw a match as a loop clear every tile that was looped around. I didn’t get around it, partly due to time, but partly because I enjoyed the challenge of low space. It’s not as big of a problem in timed mode, where you usually can’t get past tier 3-4.
I think the best strategy, if you want to play for score in endless mode, would be to focus on a single color which you try to build a high-tier chain for, while other pieces, you try to match as longer chains to keep out of the way. But this is easier said than done. I may need to experiment with less colors for a post-jam version.