Very cool concept and execution is really good!
I didn't beat all levels but I had a lot of fun playing. It took me a bit to realise the tower is also attackable even though you mention that. An overall HP of the tower would've made it a bit easier for players to grasp that. I like the way you communicate health of each piece, so one like that for the tower would've been great.
Being able to add more pieces onto the board when I rolled a 6 was great but I was hoping the AI would do the same.
Overall solid and fun submission! Good job.