It is actually really great looking at all those robots from different anime fight together in one game. (It probably costs Banpresto tons of money to buy all those licenses from different anime creators)

The difficulty and the length of the game varies greatly upon the title as well. Titles may vary from 3X episodes to 100+ episodes and the last boss may be killed with 1shot to a boss who can endure hundreds of attacks (maybe)

The game system is quite similar throughout the series except for minor(?) changes. The battlefield looks like a map of a SRPG with small robots all around the map. When you attack an enemy with a weapon, it changes to a 1 vs 1 (or until 1 vs 4 for Alpha 2) screen where one robot attacks and the other robot counters/evades/defends.