The Wild Wings of Phoenix Deluxe Slot

The wild wings of Phoenix deluxe is a 5-reel 3 row slot from Booming games based around the Aztec theme. In the back of the slot grid, you can see an Aztec temple and the enchanting music adds to the theme as well. The game can be played from a starting bet of 10cents and the maximum win you can achieve on this game is 5000x. The game has 6 premium symbols that pay from 50x to 20x on connections of 5 of a kind and 4 minor symbols that all pay 10x on connections of 5. The base game has a mystery symbol feature where 1 to 5 reels may be fully or partially covered with mystery symbols and up on the reveal they will give one symbol. The game has a wild symbol which when triggers expand to cover the entire reel.
The bonus can be triggered by landing 3 or more scatters and you win 12 free spins. The bonus works on symbol upgrade feature which means when a wild symbol appears the lowest premium symbol from future spins gets converted to the symbol which pays higher than it. If you land two wilds then the current lowest symbol will be upgraded to two levels. Landing one, two and three wilds will give you 1, 3 and 5 free spins. You can also get 12 free spins if you land three scatters.
The bonus can be bought by paying a price of 35x your bet which I think is really cheap. If you want an upgraded bonus then by paying a price of 70x you can buy 12 free spins with 2 of the lowest symbols upgraded. Paying a price of 120x will get you a bonus round with 4 of the lowest symbols upgraded.
The mystery symbol feature is the only good aspect of them and everything else is just disappointing. The base game barely pays anything so I suggest just do bonus buys. The bonus can take a long time to trigger and for a low volatility game like this it dents your balance too much.

I have played a lot of games with this mechanism and honestly speaking this is the worst one. You see wilds appearing at a pretty good rate and connections with low symbols also occur during the first few symbols but the moment you upgrade the game dies. I must have upgrade to the last level over 10 times but never managed one single connection.