Retro Tanks is a 4 player local co-op tank skirmish game with a focus on mining various types of ore to upgrade your tank. With plenty of features such as game customisation, multiple weapons and upgrades, team-play mode, 3 vs 1 mode, single player time-attack mode, post game statistics and ribbon awards/medal system (achievements) which unlocks further game content, tank build-tester and plenty more. There's around 50 levels at present which are played in either campaign mode or free level select. The campaigns are 10 levels long and dedicated to specific set-ups, e.g. team-play campaign for 2 vs 2 games with each level carefully designed to create a tight co-op battle arena.
The tank-builder page allows players to see what each of the weapons and upgrades does, along with a pro-tip from me. Additionally, you can view the cost of all the upgrades both individually and cumulatively for the current tank-build. Something for the real mathemagicians.