First off, very fun game! The speed is the speed of the boat, I'm assuming...maybe you're going for more of a cozy casual vibe but (if speed does not already account for this) did you consider another shop item to speed up ticks? If you are thinking about going that route, a fps (fish per second) metric a la cookie clicker cps would be interesting so players can see the big number go up fast by tracking the smaller number increasing. I hit the 500 -> 200 bug too... It might have been when I increased fishing above 50 per tick? That or increasing the quality of the catch ran me over the natural population and i over fished. I also noticed in the stats, I wasn't able to increase my bonus fish chance, etc. that might just be a future feature... Loved it up until that point though!