I tried Relay Grid. Here's my feedback:
- Understanding the rules: I picked them up pretty quickly.
- Progress: I played through six levels.
- Hints: I didn't use any.
- Continuing: I kept playing after the first board, but stopped after six levels.
- Losing interest: The difficulty didn't seem to increase as I progressed, so it started to feel repetitive. I would have liked more of a challenge in the later levels.
Hope this helps!