Also you should significantly boost the mini-games rewards based on combo. An exponential function should work. Around lvl 75 the game becomes stagnant, as you are literally unable to get any significant experience or money from mini games, and the only progress you get is from buying experience for interest. Maybe base the rewards from games on level?
Base experience and money got every time fastbar fills on your experience level. This way the leveling up gets more rewarding. I can hardly see a point in getting a lvl higher than 75, as i have bought everything there is to buy in the game and another lvl up seems to change nothing at all. You should think about some kind of achievement or reward you can get indefinitely, but each time it is more expensive/require more exp. Something like Double or nothing game, but with a medal/star/whatever fancy that you can hang on the wall of your house and look at with a sense of accomplishment.
Casino games give almost no chance of winning, even with a lot of luck. You can easily enable better profit especially as later on 90% of your profit comes from the bank account anyway. Slot machine could be cool, but it absolutely needs a pre-set working time. As it is now it can roll anywhere between 0,5 to over 5 seconds, and that can sometimes get irritating as hell. Set the rolling time to about 1-2 seconds always. Adding an animation would be also nice.
Maybe think about basing the fishing on skill as well and adding a combo mater. I don't know some kind of bar that fluctuates between full and empty and you have to stop it in the middle to actually reel successfully.
You may want to work on the mini games a bit. As they are now, most of them depend on luck more than actual skill, and it gets boring pretty fast. You could easily make the target range better by boosting speed the higher the combo is. Snail hills are nice, but around 30+ combo the only factor deciding your score is luck. I got 69 only because the snails dropped in an almost straight line, but most of the time its impossible to go beyond 30. Maybe boost the bucket moving speed or base it on mouse movement instead of keyboard. The 'whack a seal' could also use a progressive difficulty, more evident than it is now. Maybe limit the number of seals that may appear at the same time based on current combo, and show time as well. Or maybe start with only 2 pools open and activate the other 4 as the game progresses.
A few smple improvements could do great things. Some kind of abilities that you get on higher lvls would be nice, nothing strong though, like an ability to move a single unit between your teritories every round, or a few % attack/defense bonus. A team system is a requirement for this to truly be a multiplayer game. Regulating time for moving/deploying units would be a good addition. You can throw away a 1 vs 1 battle mode (not the quick one), becouse it simply makes a game booooring. Thats for starters. Once the game has a decent base it could use an expansion, but thats for the future.
The strategy I use is to choose a random dot, place is far from the rest, then I find all the dots connected to that particular one and place them on an arch or line, so that no lines beetween them cross. If its still impossible to tell how to win in one-two moves, I choose one of the dots on the line, and do the same thing i did with the previous one. If its impossible to do so on an arch or a line then that means the dot you choose is one surrounded by others. At this point i prefer to find another that is an 'external' one, so to speak.