Quadradius is obviously a great game. The major problem is that the games are too drawn out. Even worse, a huge portion of the playing time is spent playing games that are almost certainly already decided. This is because the game keeps on going with one player controlling most of the board, having most of the powers, but no fast way to eliminate the rest of the opponents pieces. Meanwhile, the opponent plays on, hoping for a big stroke of luck. This part is quite boring for both players.
It is not clear how to solve this problem. One good solution is making the board a little smaller, like you attempt with the 9*9 board. However that board has a different large flaw: The height. The 8 height ensures a dynamic first line on the 4th and 5ht rows. If the board is 9 high, one player will get the 4th row, one player will get the 6th row, with the 5th row between them. They then both have plenty of space to walk around in and get orbs, which means that the game is mostly decided by the powers you get here. The simple solution is to make a 9*8 or 8*8 board.
Other than that I have some loose ideas for things that can stop games that are almost certainly already decided. There could by a counter, that counts some sort of value, including some combination of number of powers, number of pieces, and number of squares your pieces can move to. When one player reaches 80% of the total in this score, the opponent has one move to revert the balance, or he loses the game. The percentage should be set high enough that it virtually never ends games where the loser still has a good chance, but also low enough to actually end some games. I expect that this is not problematic.
Also another thing that seems minor, but actually plays a large factor in drawing the games out is invisibility. If the opponent is moving around with an invisible piece, the player will often try to get it using powers that have no effect unless the invisible piece is in range. If he has two such powers, each round requires 4 actions instead of two, plus it takes some time for the graphics to show. This takes way too long. Either you should not be able to activate the powers if they have no visible effect, or there should be some way to automate this.