1. Each color contains each number once.
2. Identical numbers cannot be connected. However, identical numbers can be next to each other. There can also be multiple 4's, or any number, on the same row or column.
Numoly reminds me a bit of Strimko Gold. If you like one either game, then you'll like the other.
I've solved about 80 levels so far. I paid $1.99, not to skip the ads, but as a token of appreciation. (According to the Leaderboard, there are only about 100 people playing this game and I'm guessing that only 20% of them paid $1.99.)
I particularly like the 4x4 & 5x5 levels - can I solve them in 30 seconds?!
I've only done one 8x8. Took about 15 minutes. In part because everything is too small to read.