In one of Rival casinos I had a balance of 100€ and I started to play this game. The inspiration for this game is ancient tribes, as far as I could tell. The game had bird, fish, drums and other symbols. I couldn't really say that they all looked cohesive, but the color scheme was in purple shades and looked good so even though I didn't feel like all symbols fit the theme, the game itself looked like an eye candy.
From technical point of view, Thunderbird is a regular 5 reel and 50 payline slot game, and luckily the paylines aren't fixed so player can choose to play on lower amount of paylines. Bonus wise the game offers a free spins round triggered by scatter symbols. My favorite part of the game was the wild symbols which gave 2x multiplied winnings. The wilds appeared really often but still, in my hour long session, not even once I had a win over 30x bet on base game and that win was because of a 5oak combination with wilds.
One of the most important things about this game is the fact that it is very expensive because the minimum bets are 0.50€. I wasn't brave enough to bet more than the minimums and when I triggered free spins for the first time I had great expectations. When you get 3 fish symbols, you get 10 free spins and for more scatters- more spins, up to 50. However the spins have 1x multiplier which doesn't really help. The small multiplier is being compensated with wilds that expand on winning combinations on first 4 reels. So in the free spins if you get 3 or more yellow fish symbols, they add 5 free spins on which 1st reel is a stacked wild. I managed to get this feature a few times in my session and I have to say- when I didn't get it, my winnings were less than 10x bet, so I think that the only possibility to get a decent win on free spins is if you get the super spins and wilds, which can be hard. Once I managed to get 20 free spins and the super spins too but it paid me only 20x bet, and my biggest win on free spins was 44x bet.