There are a few similarities between Ogame and SpaceHunt, this article explains the differences.
SpaceHunt is a game that limits players in a good way, you need to be responsible not only with your resources, but with how you manage your space. This also increases collaboration with your guild since each member tends to adopt a different role: the resource gatherer, the attacker (many hangars to store and launch a bigger fleet), the upgrader (high research levels), the unit builder (massive storage), etc.
Units: The limitation on units in SpaceHunt makes you think more about your strategy than just having fleets of millions of units like in Ogame.
SpaceHunt is less complex than Ogame, without losing playability or strategy. For example:
SpaceHunt aims to be fun for both power and sporadic players and tackles the reason most people abandon Ogame, abuse by high-level players.
At SpaceHunt, the Interplanetary Code forbids high-level users from attacking very low-level ones, which makes the game more fun and allows for new players to grow without fear or despair of losing everything and becoming the slave of someone else.
On Raids that end in a Draw, the Attacker can also grab some debris from the battle, otherwise, players don't attack in fear of losing their assets in case of a close call.
When a strong Raid is incoming, Defenders that know they are going to be annihilated, in Ogame they need to set a mission to send their units away and calculate when they want them back. In SpaceHunt, players just need to assign them in a mission, fill those units with resources, and the units won't participate in the Battle. Once the Battle is finished, they can cancel the mission as if nothing happened.
Since a few years back, Ogame has become a pay to win game, rich players just spend hundreds of dollars and crush everyone else, then the players leave until another Universe is launched.
SpaceHunt is not, and will never be, a pay to win game.