The rules are pretty thin on the ground here. We've uncovered a couple of situations not easily resolved without house rules and the resolution of which has huge consequences upon the possible balance of play, so you find yourself playtesting rather than playing. The situations we're unclear on are:
1) What if cannot move? It can and does happen. No legal moves exist. Do you miss your turn? Have you lost the game? Has your opponent lost the game? Is it a stalemate? Either way, it's pretty easy to achieve.
2) Can you move your bucket ONTO a two high pile of sand FROM a one high pile of sand? Rules are ambiguous here, they simply state the ONTO part is legal and then show examples which conveniently don't include the FROM anywhere but ground level. This makes a huge strategic difference uncovered quickly if two adults play.
We'll probably find other uncertainties the more we play. It is fun and cute, and simple, but our greatest challenge for now is these as we're both playing two buckets down up front (figuring we want buckets on the ground) then all the Big base sand piles so that the opponent can't get up on it, which covers eight of the nine spaces and then we just shove them around forever until a mistake is made in a seemingly endless sequence for as long as we both manage to move the one empty space to be adjacent to one our own buckets the opponent can't play a small sand pile.
Bizarre. We're working on it still. Anyone else have any experience, house rules, or perhaps an author on-line reading with clarifications of playtesting premises not clarified in the published rules?
1) What if cannot move?
1) The best way to resolve this is with, yes, that's right, a house rule, but not any of the ones you suggest. The house rule should go like this: "No move is legal that deprives your opponent of a legal move on his next turn."
2) Can you move your bucket ONTO a two high pile of sand FROM a one high pile of sand? Rules are ambiguous here...
2) Not really. The rules only provide for the CONstruction of sand castles, not for their DEconstruction. Deconstruction is clearly contrary to the spirit (if not the letter) of this game. Topitop is about building sand castles, not dismantling them. Of course, you can always make deconstruction a house rule if you want. But then, I fear, by expanding the rule set of this simple game you needlessly diminish its elegance.
...we just shove them around forever until a mistake is made in a seemingly endless sequence for as long as we both manage to move the one empty space to be adjacent to one our own buckets...
Topitop is either:
1. a P1 win. OR
2. a P2 win. OR
3. perpetual motion with perfect play, as you say, OR
4. just fine as it is.
Given the opening scenario you outline, I don't see how #3 is possible in my experience. I have played this opening over and over again by myself. If P1 makes his first move on the center starfish, in a dozen moves or less (most of them forced) he can so maneuver P2's pails that they are isolated from the empty starfish. On the next move, of course, P2 commits suicide by being forced to place a small sand pile on the empty starfish. So I think that #1 is correct: a clear victory for P1 every time -- or at least P1 is heavily favored.
A well known remedy for 1st player advantage might be invoked here: the Pie Rule. For Topitop a 4-move ballot seems appropriate. One player proposes 4 moves by playing them on the board: the first move for Red, let's say, the second for Blue, the third for Red and the fourth for Blue. The other player then chooses whether to play the fifth move as Red or to take over the Blue pails. This metarule is used in many abstract strategy games.
Of course, your experience as well as mine is merely anecdotal. What's needed is a computer simulation and analysis. Short of that, we cannot know for certain whether the game is broken or not.