Great game, may I just suggest that you double the sensitivity of movement to 2X what it is now... or perhaps put in a function to change the movement what you want. I find it the movement to be quite resistant and this took away from the fun, otherwise, I loved it.
The starting speed of 100 is a little off putting, I personally feel that I enjoyed the 100 by 100 gameplay because it made it possible to reach higher speeds without going through the first 500 slightly boring speeds. If you do decide to keep the start at 100, please reset the leaderboards even though I am near the top 100 -_-. I must say about the overlapping problem, you have reduced it significantly, however I still saw a red wall which I passed through with no problem. Keep up the good work
I'm working on a fix that should please everyone for the starting speed issue. The next version will reset the high score table anyway. Also thanks for the comment on the overlapping issue, I am aware of one thing I didn't fix on the previous version that I'll try and address for 1.0.13 :)
It gets a little tedious towards the end, so may I suggest a more varied and also larger (3-4X) landscape for more strategic workspace. Another thing that would be awesome is a multiplayer option, perhaps an online pack. Maybe Instead of winning in a certain amount of moves for gold, it could be based on how much health your collective team has at the end of the battle. Other than these suggestions, this is a neat little game and is worth a play-through or 2. Have fun everyone.
Here are some tips for the hard badge: Ninjas can only stay stealthed for a average amount of time and you can utilize this by having attacking towers at the spawn point (preferably temples because of their speed hits). Once you have towers at the spawn point place strong towers near your gems, the ninja stealth will wear off near your gems and they will be obilitorated due to low health. It is preferable that you build and upgrade your towers near the gems first for they wont get many kills later because of the spawn point towers and use Meteors obviously. + if this helped.
It's possibly the image effects - try turning them off in the options menu, and let me know how you get on :D