This looks nice but the initial sign-up barrier seems unnecessary. I don't want to create an account and validate my e-mail address before knowing what the challenges and the app actually are. This also introduces a 30s to 2m window until the confirmation e-mail is delivered.

It might improve the flow to first letting them play a challenge (does not have to be daily challenge, e.g., just the demo tetris-like game from the starting page) and then introduce the account sign up afterward.

To comment on the actual game (tested on Firefox desktop):

- The yellow box with hints overflows (and is cut off) in the middle of the second paragraph

- The site layout appears to be optimized for mobile (portrait) screens. But the actual interactive elements look to small for touch targets. For desktops (if that is a target), consider using the horizontal space more (e.g., for the box with hints or the leaderboard(s))

- The tooltips on the actions at the top of the lines games board were not in English (appear to be maybe Spanish/Portuguese). Seems like a missing translation (my language preferences are en;de).

- the lines game itself was fine, the idea is okay but I don't think I want to play more than 2-3 rounds of it (which is okay for a daily challenge-ish game). An improvement might be to highlight (with a light background on the board) what combinations of piece layouts are possible after placing the first block (e.g., the straight piece only has 4 possible layouts after the first block and one after the second).

Thanks so much for taking the time to test it and giving such thorough feedback!

Yellow box: You were totally right. The copy was a bit too long for certain browser/font configurations. I'm shortening the text so it fits perfectly without breaking the layout.

Layout/Targets: Spot on. The game was built strictly as for mobile to be played with one hand. Playing it on a big monitor right now is probably a bit of a torture! ;)

Tooltips: Nice catch! I had hardcoded the title attributes in Spanish and completely forgot to pass them through the translation dictionary. Fixed and deployed!

Highlighting piece projections: This is actually a really nice UX idea! I originally left it out because part of the core challenge is forcing the player to mentally visualize the rotations and placements, but I completely see how it would reduce the cognitive load.

Really appreciate the honest review!