TL;DR: Mediocre variety, mediocre gameplay (read extended for breakdown), abysmal runtime, abysmal control over unlocking the gallery.
2/5.
Gameplay:
You click a tile, an event based on the colour of that tile occurs at random. Every 3-4 tiles you can bang the girl for more HP.
- Blue tiles are positive, either giving you back some HP (-1 to +9 instead of -6) or giving you "dick power" which is used to tempt the girl.
- Purple tiles are half-and-half. They either give you more "dick power" or decrease your "dick power".
- Grey tiles are blank.
- Yellow tiles are treasure chests, and are positive (+arousal to the girl).
- Red tiles are very negative (up to -16 HP).
There are a few lanes and you can only move up, down, left or right. Going back to a tile you already were at is considered as a blank tile that doesn't add to your ability to bang the girl for an HP refund, which means you almost never want to do that.
The way you play is just trying to locate the safest path you can - which is to say, taking the lowest number of red tiles and highest number of blue tiles as you can while you head to the right. Along the way you want to reach a high enough arousal rating on the girl and a high enough "dick power" for yourself to get the ending you wanted.
That's all there is to it.
All in all, this will take you ~5-10 minutes to get sick of, and then an unquantifiable amount of time to hunt down the remaining CGs, because you have no control over what events the game spawns. If you're lucky, you'll have everything with 2-3 runs. If not, you'll have a particular treasure chest event missing on a particular level, and my suggestion at this point is to download the cheat mod and force it to spawn.
In conclusion: RNG nonsense, boring gameplay, zero effort, zero challenge, completely mediocre dross which has only one saving grace: the art and availability of a gallery.
2/5.