You can play BlockTanks.io in a99.io as unblocked.
In the tank you direct, you must be from the Red or Blue team and whichever team you are from, the other team will be your opponent. The bullets you throw can touch the opponent by bouncing off the wall, or the bullet fired by the opponent can bounce and touch you. There are 5 Modes in the game and the names of these modes are as follows: Battle Royale, Free-For-All, Payload, Teams (8V8), Teams (3V3). The more opponents your team destroys in 6 minutes, the closer you will be to winning.