Sound like a cool idea. just as a heads up there is a cap to how fast fish can spawn. its a relatively high cap so its nothing to worry about but in the sandbox mode i will add unlimited fish spawning. oh and fish spawning is very buggy when it reaches a certain value and so is movement speed. movement speed has a more obvious cap and the reason being anything over that will be extremely buggy. but if you so wish i will uncap it and add a sandbox mode which does sound pretty cool. Would you like to see anymore upgrades added to the game and if so what should the upgrades do?